The Effect of Relative Pubertal Maturation and Perceived Popularity on Symptoms of Depression and Social Anxiety in Adolescent Boys and Girls

Research has shown that adolescents - particularly girls - who mature relatively early often experience more internalizing problems. This effect is thought to be partially driven by psychosocial mechanisms, but previous research based relative pubertal maturation on complete samples or population standards, instead of considering the adolescents' direct peer environment. In the current study the level of adolescents' pubertal development was assessed relative to their classmates in order to examine relative pubertal maturation. The effects of adolescents' relative pubertal status, and their perceived popularity, on symptoms of social anxiety and depression in adolescents were studied. All analyses were also performed for absolute pubertal maturation. Participants were 397 young adolescents (Mage = 13.06, SD = 0.36, 49.9% girls) at timepoint 1, and 307 (Mage = 14.08, SD = 0.36, 50.5% girls) at timepoint 2. A significant positive relationship was found between relative pubertal timing and symptoms of depression for girls but not boys. Social anxiety symptoms were not significantly related to relative pubertal timing in either sex. Relative pubertal maturation had no effect on change in or persistence of depressive and social anxiety symptoms one year later. The effects of the comparison with the immediate peer environment, did not seem to explain more variance in internalizing symptoms than the effects of early maturation.

Increased interference from conflicting perspectives and gender differences: A longitudinal study during adolescence

Adolescents need to develop adequate perspective-taking skills to successfully navigate their increasingly complex social environments. This study investigated adolescents' development of the cognitive processes of egocentric and altercentric interference that influence perspective-taking abilities. Using the Dot Perspective Task, participants' (N = 803; 50.9% female) egocentric and altercentric interference was measured during 3 consecutive years from 12 to 14 years of age. Linear mixed model analyses showed that whereas overall task performance improved over time, egocentric and altercentric interference increased over time. These results suggest that perspective taking develops at slower rates when there are conflicting perspectives than in situations with no conflict. Moreover, we found that girls showed less egocentric interference than boys. This result provides task-based evidence that supports previous findings of higher self-reported perspective taking in adolescent girls than in adolescent boys.

A Few Close Friends? Adolescent Friendships' Effect on Internalizing Symptoms Is Serially Mediated by Desire for More Friends and Social Goal Orientation

Interpersonal connection is a fundamental human motivation, and the extent to which it is fulfilled is a strong predictor of symptoms of internalizing disorders such as social anxiety and depression, perhaps especially during the "social reorienting" period of adolescence. However, little is known about the contribution to this effect of the individual's social motivations, which are intensified during adolescence. Furthermore, social goal orientation - an individual's priorities and intentions in social interactions - is an important predictor of vulnerability to internalizing symptoms. Adolescents spend most of their waking lives in classrooms, bounded social networks with a limited pool of candidates for befriending. This study investigated whether friendships within one's class protects against internalizing symptoms in part by reducing the desire for more classmate friendships, which may tend to promote maladaptive social goals. Participants were 423 young adolescents (M age = 13.2, sd = 0.52 years; 49.4% girls). As predicted, adolescents' number of reciprocated classroom friendships had a protective effect on internalizing symptoms which was serially mediated by desire for more such friendships, and social goal orientation. However, only demonstration-avoidance goals significantly predicted internalizing symptoms. Unreciprocated friendship nominations were unexpectedly associated with stronger desire and more social anxiety symptoms. The results suggest that the effect of number of friends is mediated by the individual's thoughts and feelings about their number of friendships, such that a strong desire for more friendships promotes maladaptive goals, oriented toward social status and consequently less oriented toward the cultivation of interpersonal intimacy with the friends they already have.

Social network position, trust behavior, and neural activity in young adolescents

Our social interactions take place within numerous social networks, in which our relationships with others define our position within these networks. In this study, we examined how the centrality of positions within social networks was associated with trust behavior and neural activity in 49 adolescents (M_age = 12.8 years, SD_age = 0.4 years). The participants played a trust game with a cartoon animation as a partner, which showed adaptive behavior in response to the participant and was generally untrustworthy. Social network positions were obtained in secondary school classrooms where the participants and their classmates reported on who their friends were. Using social network analysis, a score was calculated that indicated the centrality of everyone's position within the friendship network. The results showed that more central social network positions were associated with higher levels of initial trust behavior, although no evidence was found for a relationship between network position and the adaptation of trust behavior. The results of the functional MRI analyses showed that the centrality of the network positions was positively associated with caudate activity when making trust decisions. Furthermore, the adolescents with more central network positions also showed stronger increases of caudate activity when the partner's return was processed compared to the adolescents with less central network positions. The current study provides initial evidence that social network positions in friendship networks relate to socio-cognitive behavior and neural activity in adolescents.

Preliminary data on oxytocin modulation of neural reactivity in women to emotional stimuli of children depending on childhood emotional neglect

Sensitivity for rewarding cues and distress signals from children is fundamental to human caregiving and modulated by the neuropeptide oxytocin. In a functional magnetic resonance imaging study, we investigated whether oxytocin regulates neural responses to reward or distress cues form children. In a placebo-controlled, within-subject design, we measured neural responses to positive, negative, and neutral cues from children in 22 healthy female subjects who received oxytocin (24 IU) versus placebo. Further, based on current literature, we hypothesized that oxytocin effects are modulated by experiences of childhood trauma. The task elicited valence-specific effects-positive images activated the ventromedial prefrontal cortex, left anterior cingulate cortex, and right putamen, and images of children in distress activated the bilateral amygdala, hippocampus, and right medial superior frontal cortex. The effects of oxytocin depended on subjective reports of childhood emotional neglect. Self-reported neglect interacted with oxytocin administration in the amygdala, hippocampus, and prefrontal areas. In individuals with higher scores of emotional neglect, oxytocin increased neural reactivity of limbic structures to positive and neutral images. Our findings need replication in larger samples and can therefore be considered preliminary but are in line with the recent literature on the modulating effect of childhood adversity on the sensitivity to oxytocin administration.

Neural, behavioural and real-life correlates of social context sensitivity and social reward learning during interpersonal interactions in the schizophrenia spectrum

OBJECTIVE

Recent findings suggest that diminished processing of positive contextual information about others during interactions may contribute to social impairment in the schizophrenia spectrum. This could be due to general social context processing deficits or specific biases against positive information. We studied the impact of positive and negative social contextual information during social interactions using functional neuroimaging and probed whether these neural mechanisms were associated with real-life social functioning in schizophrenia spectrum disorders.

METHODS

Patients with a schizophrenia spectrum disorder (N = 23) and controls disorder (N = 25) played three multi-round trust games during functional magnetic resonance imaging scanning, with no, positive and negative information about the counterpart's trustworthiness, while all counterparts were programmed to behave trustworthy. The main outcome variable was the height of the shared amount in the trust game, i.e. investment, representing an indication of trust. The first investment in the game was considered to be basic trust, since no behavioural feedback was given yet. We performed region-of-interest analyses and examined the association with real-life social functioning using the experience sampling method.

RESULTS

Social contextual information had no effect on patients' first investments, whereas controls made the lowest investment after negative and the highest investments after positive contextual information was provided. Over trials, patients decreased investments, suggesting reduced social reward learning, whereas controls increased investments in response to behavioural feedback in the negative context. Patients engaged the dorsolateral prefrontal cortex less than controls during context presentation and showed reduced activity within the caudate during repayments. In patients, lower investments were associated with more time spent alone and social exclusion and lower caudate activation was marginally significantly associated with higher perceived social exclusion.

CONCLUSION

The failure to adapt trust to positive and negative social contexts suggests that patients have a general insensitivity to prior social information, indicating top-down processing impairments. In addition, patients show reduced sensitivity to social reward, i.e. bottom-up processing deficits. Moreover, lower trust and lower neural activation were related to lower real-life social functioning. Together, these findings indicate that improving trust and social interactions in schizophrenia spectrum needs a multi-faceted approach that targets both mechanisms.

Differences in executive abilities rather than associative processes contribute to memory development

Children's learning capabilities change while growing up. One framework that describes the cognitive and neural development of children's growing learning abilities is the two‐component model. It distinguishes processes that integrate separate features into a coherent memory representation (associative component) and executive abilities, such as elaboration, evaluation, and monitoring, that support memory processing (strategic component). In an fMRI study using an object‐location association paradigm, we investigated how the two components influence memory performance across development. We tested children (10–12 years, n = 31), late adolescents (18 years, n = 29), and adults (25+ years, n = 30). For studying the associative component, we also probed how the utilisation of prior knowledge (schemas) facilitates memory across age groups. Children had overall lower retrieval performance, while adolescents and adults did not differ from each other. All groups benefitted from schemas, but this effect did not differ between groups. Performance differences between groups were associated with deactivation of the dorsal medial prefrontal cortex (dmPFC), which in turn was linked to executive functioning. These patterns were stronger in adolescents and adults and seemed absent in children. Thus, the children's executive system, the strategic component, is not as mature and thus cannot facilitate memory performance in the same way as in adolescents/adults. In contrast, we did not find age‐related differences in the associative component; with activity in the angular gyrus predicting memory performance systematically across groups. Overall, our results suggest that differences of executive rather than associative abilities explain memory differences between children, adolescents, and adults.

Intrinsic network interactions explain individual differences in mentalizing ability in adolescents

Mentalizing is an important aspect of social cognition and people vary in their ability to mentalize. Despite initial evidence that mentalizing continues to develop throughout adolescence, it is unclear which neural mechanisms underlie individual variability in mentalizing ability in adolescents. Interactions within and between the default-mode network (DMN), frontoparietal network (FPN) and cingulo-opercular/salience network (CO/SN) have been related to inter-individual differences in cognitive processes in both adults and adolescents. Here, we investigated whether intrinsic connectivity within and between these brain networks explained inter-individual differences in affective mentalizing ability in adolescents. Resting-state brain activity was measured using functional MRI and affective mentalizing ability was defined as correct performance on the Reading the Mind in the Eyes test performed outside the scanner. We identified the DMN, FPN and CO/SN, and within and between network connectivity values were submitted to a bootstrapping enhanced penalized multiple regression analysis to predict mentalizing in 66 young adolescents (11-14 years). We showed that stronger connectivity between the DMN and the FPN, together with lower within-network connectivity of the FPN and the CO/SN predicted better mentalizing performance. These novel findings provide insight into the normative developmental trajectory of the neural mechanisms underlying affective mentalizing in early adolescence.

Social Cognition and Friendships in Adolescents With Autistic-Like Experiences and Psychotic-Like Experiences

Autism spectrum conditions (ASC) and schizophrenia spectrum conditions (SSC) are both characterized by changes in social-cognitive functioning. Less is known about the overlap and the differences in social-cognitive functioning when comparing individuals with subclinical levels of ASC and SSC, while studies in non-clinical samples have the benefit of avoiding confounds that are present in clinical groups. Therefore, we first examined how autistic-like experiences, positive psychotic-like experiences and the co-occurrence of both correlated with the performance on an extensive battery of social cognition tasks in young adolescents. Second, we examined the effect of autistic-like experiences, psychotic-like experiences and their co-occurrence on friendships in daily life. A total of 305 adolescents (Mage = 12.6, sd = 0.4, 147 boys) participated in the current study. A battery of social cognition tasks, comprising the Reading the Mind in the Eyes task, Dot perspective task and trust game were individually administered in a classroom setting, along with a friendship peer nomination questionnaire. Results indicated no evidence for a relationship between the performance on the social cognition battery and subclinical experiences of autism and/or psychosis. However, results did show that the amount of autistic-like experiences of adolescents were associated with being less often selected as a friend by their peers. By contrast, no relationship between self-reported friendships and autistic-like experiences was found. Neither a relationship between friendships and psychotic-like experiences was reported. This study provides initial evidence that information provided by peers may shed light on (altered) social behavior associated with autistic-like experiences that is not apparent on performance measures, as well as elucidate possible differences between autistic- and psychotic-like experiences.

Functional network interactions at rest underlie individual differences in memory ability

Intrinsic network interactions may underlie individual differences in the ability to remember. The default mode network (DMN) comprises subnetworks implicated in memory, and interactions between the DMN and frontoparietal network (FPN) were shown to support mnemonic processing. However, it is unclear if such interactions during resting-state predict episodic memory ability. We investigated whether intrinsic network interactions within and between the DMN and FPN are related to individual differences in memory performance. Resting-state activity was measured using functional MRI in healthy young adults followed by a memory test for object–location associations that were studied 3 d earlier. We identified two subnetworks within the DMN, the main-DMN and the medial temporal lobe, retrosplenial cortex (MTL_RSC)-DMN. Further, we found regions forming the FPN. Memory performance was associated with lower connectivity within the MTL_RSC-DMN, and stronger connectivity between the main-DMN and FPN. Exploratory whole-brain analysis revealed stronger MTL connectivity with the left posterior parietal cortex that was related to better memory performance. Furthermore, we found increased task-evoked activation during successful retrieval within the main-DMN and FPN, but not within the MTL_RSC-DMN. In sum, lower intrinsic connectivity within the MTL_RSC-DMN, combined with stronger connectivity between the main-DMN and FPN, explain individual differences in memory ability.

Methylphenidate during early consolidation affects long-term associative memory retrieval depending on baseline catecholamines

RATIONALE

Synaptic memory consolidation is thought to rely on catecholaminergic signaling. Eventually, it is followed by systems consolidation, which embeds memories in a neocortical network. Although this sequence was demonstrated in rodents, it is unclear how catecholamines affect memory consolidation in humans.

OBJECTIVES

Here, we tested the effects of catecholaminergic modulation on synaptic and subsequent systems consolidation. We expected enhanced memory performance and increased neocortical engagement during delayed retrieval. Additionally, we tested if this effect was modulated by individual differences in a cognitive proxy measure of baseline catecholamine synthesis capacity.

METHODS

Fifty-three healthy males underwent a between-subjects, double-blind, placebo-controlled procedure across 2 days. On day 1, subjects studied and retrieved object-location associations and received 20 mg of methylphenidate or placebo. Drug intake was timed so that methylphenidate was expected to affect early consolidation but not encoding or retrieval. Memory was tested again while subjects were scanned three days later.

RESULTS

Methylphenidate did not facilitate memory performance, and there was no significant group difference in activation during delayed retrieval. However, memory representations differed between groups depending on baseline catecholamines. The placebo group showed increased activation in occipito-temporal regions but decreased connectivity with the hippocampus, associated with lower baseline catecholamine synthesis capacity. The methylphenidate group showed stronger activation in the postcentral gyrus, associated with higher baseline catecholamine synthesis capacity.

CONCLUSIONS

Altogether, methylphenidate during early consolidation did not foster long-term memory performance, but it affected retrieval-related neural processes depending on individual levels of baseline catecholamines.

DRD2 Schizophrenia-Risk Allele Is Associated With Impaired Striatal Functioning in Unaffected Siblings of Schizophrenia Patients

A recent Genome-Wide Association Study showed that the rs2514218 single nucleotide polymorphism (SNP) in close proximity to dopamine receptor D2 is strongly associated with schizophrenia. Further, an in silico experiment showed that rs2514218 has a cis expression quantitative trait locus effect in the basal ganglia. To date, however, the functional consequence of this SNP is unknown. Here, we used functional Magnetic resonance imaging to investigate the impact of this risk allele on striatal activation during proactive and reactive response inhibition in 45 unaffected siblings of schizophrenia patients. We included siblings to circumvent the illness specific confounds affecting striatal functioning independent from gene effects. Behavioral analyses revealed no differences between the carriers (n= 21) and noncarriers (n= 24). Risk allele carriers showed a diminished striatal response to increasing proactive inhibitory control demands, whereas overall level of striatal activation in carriers was elevated compared to noncarriers. Finally, risk allele carriers showed a blunted striatal response during successful reactive inhibition compared to the noncarriers. These data are consistent with earlier reports showing similar deficits in schizophrenia patients, and point to a failure to flexibly engage the striatum in response to contextual cues. This is the first study to demonstrate an association between impaired striatal functioning and the rs2514218 polymorphism. We take our findings to indicate that striatal functioning is impaired in carriers of the DRD2 risk allele, likely due to dopamine dysregulation at the DRD2 location.

Schematic memory components converge within angular gyrus during retrieval

Mental schemas form associative knowledge structures that can promote the encoding and consolidation of new and related information. Schemas are facilitated by a distributed system that stores components separately, presumably in the form of inter-connected neocortical representations. During retrieval, these components need to be recombined into one representation, but where exactly such recombination takes place is unclear. Thus, we asked where different schema components are neuronally represented and converge during retrieval. Subjects acquired and retrieved two well-controlled, rule-based schema structures during fMRI on consecutive days. Schema retrieval was associated with midline, medial-temporal, and parietal processing. We identified the multi-voxel representations of different schema components, which converged within the angular gyrus during retrieval. Critically, convergence only happened after 24-hour-consolidation and during a transfer test where schema material was applied to novel but related trials. Therefore, the angular gyrus appears to recombine consolidated schema components into one memory representation.

DOI:http://dx.doi.org/10.7554/eLife.09668.001

To make sense of the world around us, we constantly try to work out the relationship of new information to other things that we already know, and sort our knowledge into pre-existing mental frameworks, or “schemas”. This makes learning new things that are related to a schema, as well as remembering this knowledge, easier. The process of making these mental connections is thought to involve an extensive brain network. Separate types of information are stored in different brain regions within this network, yet to link this information together, the brain must combine them into a single representation.

Wagner et al. have now investigated which brain regions are involved in recombining separate information. Human volunteers were trained to interpret the positions or colors of pairs of circles with different rules. The combination of these separate types of information formed a mental schema that could be used as a “weather forecast”. The design of the experiment meant that measuring the brain activity of the volunteers during the task (using a technique called functional magnetic resonance imaging) allowed the brain regions involved in retrieving the different parts of such a schema to be distinguished.

Twenty-four hours later volunteers returned to use the mental schemas that they had learned to predict the weather. Retrieving which weather conditions the circle pairs represented activated a network of regions in the volunteers’ brains. Further analysis revealed that some of these regions showed specific activity patterns in response to remembering information about only one element of the task (for example, only the rules or only the visual information). However, the different aspects of the task all appeared to be integrated by a brain region called the angular gyrus. This suggests that the angular gyrus is responsible for combining separate memory parts and pieces of information into a single representation. It is able to do so by connecting to brain regions that code for such specific aspects, although this only occurs 24 hours after the mental schemas have been established.

Future studies could investigate the result of damage to the angular gyrus: different pieces of information might not be combined, or could result in an incorrect memory during retrieval. Finally, since the angular gyrus has been related to a wealth of different mental processes, it remains a challenge for future research to "converge" these findings and to understand the underlying computations.

DOI:http://dx.doi.org/10.7554/eLife.09668.002

Different developmental trajectories for anticipation and receipt of reward during adolescence

Typical adolescent behaviour such as increased risk-taking and novelty-seeking is probably related to developmental changes in the brain reward system. This functional MRI study investigated how brain activation related to two components of reward processing (Reward Anticipation and Reward Outcome) changes with age in a sample of 39 children, adolescents and young adults aged 10-25. Our data revealed age-related changes in brain activity during both components of reward processing. Activation related to Reward Anticipation increased with age, while activation related to Reward Outcome decreased in various regions of the reward network. This shift from outcome to anticipation was confirmed by subsequent analyses showing positive correlations between age and the difference in activation between Reward Anticipation and Reward Outcome. The shift was predominantly present in striatal regions and was accompanied by a significant effect of age on behaviour, with older participants showing more response speeding on potentially rewarding trials than younger participants. This study provides evidence for functional changes in the reward system which may underlie typical adolescent behaviour.

Reduced proactive inhibition in schizophrenia is related to corticostriatal dysfunction and poor working memory

BACKGROUND

Inhibitory control is central to executive functioning and appears deficient in schizophrenia. However, it is unclear how inhibitory control is affected, what the underlying neural mechanisms are, whether these deficits are related to the illness itself or to increased risk for the illness, and whether there is a relation to impairments in other executive functions.

METHODS

We used functional magnetic resonance imaging to investigate two forms of inhibitory control: proactive inhibition (anticipation of stopping) and reactive inhibition (outright stopping). Twenty-four schizophrenia patients, 24 unaffected siblings, and 24 healthy control subjects performed a modified version of the stop-signal paradigm. To assess the relation between performance on inhibitory control and other executive functions, we correlated inhibitory control indices with working memory span.

RESULTS

Compared with control subjects, proactive inhibition was reduced in patients and siblings. Reactive inhibition was unaffected. Reduced proactive inhibition was associated with a failure to activate the right striatum, the right inferior frontal cortex, and the left and right temporoparietal junction. Activation during reactive inhibition was unaffected. Those patients with the least proactive inhibition also showed the shortest working memory span.

CONCLUSIONS

These results suggest that schizophrenia is associated with reduced proactive inhibition, probably resulting from corticostriatal dysfunction. This deficit is related to an increased risk for schizophrenia and likely reflects a general executive function deficit rather than a specific inhibitory control impairment.

Exaggerated brain activation during emotion processing in unaffected siblings of patients with schizophrenia

BACKGROUND

Schizophrenia is characterized by impaired social cognition, including emotion processing. Behavioral studies have reported impaired performance on various emotion processing tasks, and imaging studies in patients have observed aberrant activity within the underlying neural circuitry. Also, subjects at increased genetic risk of developing schizophrenia, including unaffected siblings of patients, show behavioral impairments in emotion processing. It is unclear, however, whether and how the underlying neural system is disrupted in these subjects. In this study, we investigated whether siblings of patients with schizophrenia show abnormal brain activation during basic emotion processing.

METHODS

Brain activity was measured using functional magnetic resonance imaging in 24 unaffected siblings of patients with schizophrenia and 25 healthy control subjects while they viewed and rated neutral, positive, and negative pictures. None of the subjects had a psychiatric disorder, and the two groups did not differ in age, gender, or level of own, paternal, or maternal education.

RESULTS

Compared with control subjects, siblings showed increased activity within the amygdala, hippocampus, medial prefrontal cortex, posterior and anterior cingulate cortex, and middle temporal gyrus in response to emotionally arousing pictures relative to neutral pictures. No activation differences between the groups were found during the neutral stimuli, indicating that the observed hyperactivity is likely caused by abnormal emotion processing rather than impaired visuoattentional processing.

CONCLUSIONS

Our findings of hyperactivity in siblings during emotion processing suggest that functional abnormalities within the neural circuitry of emotion processing are related to the genetic risk for developing schizophrenia.

Reduced functional coupling in the default-mode network during self-referential processing

Activity within the default-mode network (DMN) is thought to be related to self-referential processing, such as thinking about one's preferences or personality traits. Although the DMN is generally considered to function as a network, evidence is starting to accumulate that suggests that areas of the DMN are each specialized for different subfunctions of self-referential processing. Here, we address the issue of functional specialization by investigating changes in coupling between areas of the DMN during self-referential processing. To this aim, brain activity was assessed during a task in which subjects had to indicate whether a trait adjective described their own personality (self-referential, Self condition), that of another person (other-referential, Other condition), or whether the trait was socially desirable (nonreferential, Control condition). To exclude confounding effects of cardiorespiratory processes on activity and functional coupling, we corrected the fMRI signal for these effects. Activity within areas of the DMN was found to be modulated by self-referential processing. More specifically, during the Self condition compared to the Other and Control condition, activity within the dorsal medial prefrontal cortex, ventral medial prefrontal cortex, and posterior cingulate cortex was increased. Moreover, coupling between areas of the DMN was reduced during the Self condition compared to the Other and Control condition, while coupling between regions of the DMN and regions outside the network was increased. As such, these results provide an indication for functional specialization within the DMN and support the notion that each area of the DMN is involved in different subfunctions of self-referential processing.

Cardiorespiratory effects on default-mode network activity as measured with fMRI

The default-mode network (DMN) consists of areas showing more activation during rest than during a task. Several authors propose some form of cognitive processing to underlie BOLD signal changes in the DMN as activity within the network is modulated by the level of effort required by the task and is positively correlated with self-referential processing. Alternatively, BOLD signal changes within the DMN may be caused by cardiorespiratory processes (CR) affecting BOLD signal measurements independent of neuronal activity. The goal of this study is to investigate whether BOLD signal changes within the DMN can be explained by CR effects. To this aim, brain activity, heartbeat, and respiration are measured during resting-state and while subjects perform a cognitive task with a high- and low-demand condition. To correct for CR effects we used RETROICOR (Glover et al., [2000]: Magn Reson Med 44:162-167) in combination with additive linear modeling of changes due to respiration volume, heart rate and heart rate variability. CR effects were present within the frequency-range of the DMN and were located in areas of the DMN, but equally so in other areas. After removal of CR effects, deactivation and resting-state connectivity between the areas of the DMN remained significant. In addition, DMN deactivation was still modulated by task demand. The same CR correction method did remove activation in task-related areas. We take these results to indicate that the BOLD signal within the DMN cannot be explained by CR effects alone and is possibly related to some form of cognitive neuronal processing.