Multiple expressions of "expert" abnormality gist in novices following perceptual learning

With a brief half-second presentation, a medical expert can determine at above chance levels whether a medical scan she sees is abnormal based on a first impression arising from an initial global image process, termed "gist." The nature of gist processing is debated but this debate stems from results in medical experts who have years of perceptual experience. The aim of the present study was to determine if gist processing for medical images occurs in naïve (non-medically trained) participants who received a brief perceptual training and to tease apart the nature of that gist signal. We trained 20 naïve participants on a brief perceptual-adaptive training of histology images. After training, naïve observers were able to obtain abnormality detection and abnormality categorization above chance, from a brief 500 ms masked presentation of a histology image, hence showing "gist." The global signal demonstrated in perceptually trained naïve participants demonstrated multiple dissociable components, with some of these components relating to how rapidly naïve participants learned a normal template during perceptual learning. We suggest that multiple gist signals are present when experts view medical images derived from the tens of thousands of images that they are exposed to throughout their training and careers. We also suggest that a directed learning of a normal template may produce better abnormality detection and identification in radiologists and pathologists.

Mortality Associated With Opioid Overdose: A Review of Clinical Characteristics and Health Services Received in the Year Prior to Death

OBJECTIVE

To assess missed opportunities for reducing fatal opioid overdoses, characteristics of decedents by opioid overdose with and without problematic opioid use who received health care services within one year of death were examined.

METHODS

Of 157 decedents in the Worcester, Massachusetts, area between 2008 and 2012, 112 had contact with the health care system. Electronic medical records were reviewed for clinical characteristics, health service use, universal precautions, and substance use disorder management. Problematic opioid use was defined as individuals having documented opioid use disorders or aberrant drug-related behavior. Data were analyzed with chi-square tests with adjusted residual for categorical variables and t tests for continuous variables.

RESULTS

Decedents were predominantly Caucasian males with a mean±SD age of 41.0±11.7. Problematic opioid use by definition meant users (N=53) had opioid use disorder as a principal diagnosis and were likely to have a comorbid substance use disorder. Decedents with nonproblematic opioid use had diagnoses of chronic pain and mental illness. They were more likely to have been seen last in surgical and subspecialty settings (29% versus 11%). The proportion with an opioid prescription was higher among those with problematic use (72% versus 37%) who also had a higher total daily morphine equivalent, compared with those with nonproblematic use (165.4±282.7 versus 55.6±117.7 mg per day).

CONCLUSIONS

Persons with problematic opioid use are a recognizable group with a high risk of death by opioid overdose whose therapeutic management needs improvement to reduce fatal outcomes. Different strategies must be developed for identifying and treating nonproblematic opioid use to reduce risk of death.

Buprenorphine-naloxone treatment responses differ between young adults with heroin and prescription opioid use disorders

BACKGROUND AND OBJECTIVES

Opioid use disorder among young adults is rising sharply with an increase in morbidity and mortality. This study examined differences in treatment response to a fixed dose of buprenorphine-naloxone between heroin (HU) and prescriptions opioids (POU) users.

METHODS

Eighty opioid dependent young adults (M = 22 years) were treated with buprenorphine-naloxone 16-4 mg/day for 8 weeks. Differences between HU (N = 17) and POU (N = 63) on changes in weekly opioid use, opioid craving, withdrawal, and depression symptoms were analyzed with mixed-effects regression models.

RESULTS

The HU had an overall mean proportion of weekly opioid use of .32 (SD = .14) compared to POU's weekly mean of .24 (SD = .15) showing a significant main effect (Z = 2.21, p = .02). Depressive symptoms (CES-D scores) were elevated at baseline for both groups (HU: M = 23.1, SD = 11.9; PO: M = 22.2, SD = 9.4), but only POU improved significantly to a score of 9.88 (SD = 7.4) compared to HU's score of 18.58 (SD = 10.3) at week 8 (Z = 2.24, p = .02). There were no significant differences in treatment retention, craving, or withdrawal symptoms.

DISCUSSION AND CONCLUSIONS

Treatment response to 16-4 mg/day of buprenorphine-naloxone was significantly diminished for heroin users relative to opioid prescription users in weekly opioid use. Heroin users also had persistent depressive symptoms suggesting the need for close monitoring.

SCIENTIFIC SIGNIFICANCE

These data suggest that young heroin users might require higher doses of buprenorphine. (Am J Addict 2017;26:838-844).

Increased Depression and Anxiety Symptoms are Associated with More Breakdowns in Cognitive Control to Cocaine Cues in Veterans with Cocaine Use Disorder

OBJECTIVE

Cue-elicited craving is a clinically important aspect of cocaine addiction directly linked to cognitive control breakdowns and relapse to cocaine-taking behavior. However, whether craving drives breakdowns in cognitive control toward cocaine cues in veterans, who experience significantly more co-occurring mood disorders, is unknown. The present study tests whether veterans have breakdowns in cognitive control because of cue-elicited craving or current anxiety or depression symptoms.

METHODS

Twenty-four veterans with cocaine use disorder were cue-exposed, then tested on an antisaccade task in which participants were asked to control their eye movements toward cocaine or neutral cues by looking away from the cue. The relationship among cognitive control breakdowns (as measured by eye errors), cue-induced craving (changes in self-reported craving following cocaine cue exposure), and mood measures (depression and anxiety) was investigated.

RESULTS

Veterans made significantly more errors toward cocaine cues than neutral cues. Depression and anxiety scores, but not cue-elicited craving, were significantly associated with increased subsequent errors toward cocaine cues for veterans.

CONCLUSIONS

Increased depression and anxiety are specifically related to more cognitive control breakdowns toward cocaine cues in veterans. Depression and anxiety must be considered further in the etiology and treatment of cocaine use disorder in veterans. Furthermore, treating depression and anxiety as well, rather than solely alleviating craving levels, may prove a more effective combined treatment option in veterans with cocaine use disorder.

Arousal facilitates involuntary eye movements

Attention plays a critical role in action selection. However, the role of attention in eye movements is complicated as these movements can be either voluntary or involuntary, with, in some circumstances (antisaccades), these two actions competing with each other for execution. But attending to the location of an impending eye movement is only one facet of attention that may play a role in eye movement selection. In two experiments, we investigated the effect of arousal on voluntary eye movements (antisaccades) and involuntary eye movements (prosaccadic errors) in an antisaccade task. Arousal, as caused by brief loud sounds and indexed by changes in pupil diameter, had a facilitation effect on involuntary eye movements. Involuntary eye movements were both significantly more likely to be executed and significantly faster under arousal conditions (Experiments 1 and 2), and the influence of arousal had a specific time course (Experiment 2). Arousal, one form of attention, can produce significant costs for human movement selection as potent but unplanned actions are benefited more than planned ones.

Breakdowns of eye movement control toward smoking cues in young adult light smokers

BACKGROUND

Many studies suggest that dependent smokers have a preference or attentional bias toward smoking cues. The purpose of this study was to test the ability of infrequent non-dependent light smokers to control their eye movements by look away from smoking cues. Poor control in the lightest of smokers would suggest nicotine cue-elicited behavior occurring even prior to nicotine dependency as measured by daily smoking.

METHODS

17 infrequent non-dependent light smokers and 17 lifetime non-smokers performed an antisaccade task (look away from suddenly appearing cue) on smoking, alcohol, neutral, and dot cues.

RESULTS

The light smokers, who were confirmed light smokers and non-dependent (MFaegerström Dependency Score=0.35), were significantly worse at controlling their eye movements to smoking cues relative to both neutral cues (p<.04) and alcohol cues (p<.02). Light smokers made significantly more errors to smoking cues than non-smokers (p<.004).

CONCLUSIONS

These data suggest that prior to developing clinical symptoms of severe dependence or progressing to heavier smoking (e.g., daily smoking), the lightest of smokers are showing a specific deficit in control of nicotine cue-elicited behavior.

Cue-induced craving in patients with cocaine use disorder predicts cognitive control deficits toward cocaine cues

INTRODUCTION

Cue-induced craving is a clinically important aspect of cocaine addiction influencing ongoing use and sobriety. However, little is known about the relationship between cue-induced craving and cognitive control toward cocaine cues. While studies suggest that cocaine users have an attentional bias toward cocaine cues, the present study extends this research by testing if cocaine use disorder patients (CDPs) can control their eye movements toward cocaine cues and whether their response varied by cue-induced craving intensity.

METHODS

Thirty CDPs underwent a cue exposure procedure to dichotomize them into high and low craving groups followed by a modified antisaccade task in which subjects were asked to control their eye movements toward either a cocaine or neutral drug cue by looking away from the suddenly presented cue. The relationship between breakdowns in cognitive control (as measured by eye errors) and cue-induced craving (changes in self-reported craving following cocaine cue exposure) was investigated.

RESULTS

CDPs overall made significantly more errors toward cocaine cues compared to neutral cues, with higher cravers making significantly more errors than lower cravers even though they did not differ significantly in addiction severity, impulsivity, anxiety, or depression levels. Cue-induced craving was the only specific and significant predictor of subsequent errors toward cocaine cues.

CONCLUSION

Cue-induced craving directly and specifically relates to breakdowns of cognitive control toward cocaine cues in CDPs, with higher cravers being more susceptible. Hence, it may be useful identifying high cravers and target treatment toward curbing craving to decrease the likelihood of a subsequent breakdown in control.

Reward, context, and human behaviour

Animal models of reward processing have revealed an extensive network of brain areas that process different aspects of reward, from expectation and prediction to calculation of relative value. These results have been confirmed and extended in human neuroimaging to encompass secondary rewards more unique to humans, such as money. The majority of the extant literature covers the brain areas associated with rewards whilst neglecting analysis of the actual behaviours that these rewards generate. This review strives to redress this imbalance by illustrating the importance of looking at the behavioural outcome of rewards and the context in which they are produced. Following a brief review of the literature of reward-related activity in the brain, we examine the effect of reward context on actions. These studies reveal how the presence of reward vs. reward and punishment, or being conscious vs. unconscious of reward-related actions, differentially influence behaviour. The latter finding is of particular importance given the extent to which animal models are used in understanding the reward systems of the human mind. It is clear that further studies are needed to learn about the human reaction to reward in its entirety, including any distinctions between conscious and unconscious behaviours. We propose that studies of reward entail a measure of the animal's (human or nonhuman) knowledge of the reward and knowledge of its own behavioural outcome to achieve that reward.

Differential effects of reward and punishment on conscious and unconscious eye movements

Very little is known about how human movements are influenced by abstract rewards and punishments relevant for human behaviour. The purpose of this study was to expand our knowledge of the behavioural effects of monetary reward and punishment. We introduced a high and low reward and punishment scheme into an antisaccade task where trials were either rewarded for a correct response (+1 or +25p) or punished for an incorrect response (-1 or -25p). The monetary value of the trial was indicated by the go signal, so subjects had to both program the location of the movement and determine the valence in the short interval before the eye movement was executed. We analysed both correct antisaccade responses and prosaccade errors. Importantly, the errors in this task can be either conscious (recognised) or unconscious (unrecognised). Saccades in both high-reward and high-punishment trials were slowed compared to saccades in low-reward and low-punishment trials, respectively. Therefore, unlike moderate rewards only (Blaukopf and DiGirolamo in Exp Brain Res 167:654-659, 2005), combining rewards and punishments and increasing motivation levels leads to a delay in movement execution during high valence trials where all actions are slowed, even errors. However, unconscious errors were differentially affected as they were speeded when punishment was high. We conclude that reward and punishment similarly influence the programming of conscious movements, but the strong saliency for punishment affords unconscious errors immunity from this delay.

The automatic extraction and use of information from cues and go signals in an anti-saccade task

In a gap antisaccade task that exogenously cues the side that subjects should antisaccade to, subjects find it hard to look away from the suddenly appearing go signal. Surprisingly, subjects are unaware of the majority of the prosaccade errors they make, and these errors remain unrecognised even when corrected by a second saccade requiring twice the amplitude [Fischer B, Weber H (1992) in Exp Brain Res 89:415-424]. This paper presents an extended antisaccade task that investigates what information, if any, subjects extract from redundant cues and go signals. In Exp. 1, multiple saccade locations were introduced and the go signal specified the goal location. A redundant cue appeared, prior to the go signal, in the antisaccade goal location (valid) or in the alternative location on the same side (invalid). In Exp. 2, motivational value was assigned to the go signal. The use of multiple locations showed that subjects automatically extract irrelevant positional information from the cue, which affects the programming of subsequent correct and error saccades. When the cued location was also the goal location, antisaccade reaction times were significantly reduced. The results from Exp. 2 showed that subjects also extract information from the go signal. Errors made to a go signal associated with a higher monetary value were initiated significantly faster than those to a lower monetary value. This study has shown that the visual stimuli used in this antisaccade task do more than initiate orienting sets: Their properties can influence the programming of both accurate actions and errors.

Differential effects of the Müller-Lyer illusion on reflexive and voluntary saccades

Research has produced conflicting evidence as to whether saccade programming is or is not biased by perceptual illusions. However, previous studies have generally not distinguished between effects of illusory percepts on reflexive saccades, programmed automatically in response to an external visual signal, and voluntary saccades, programmed purposively to a location where no signal has occurred. Here we find that voluntary and reflexive saccades are differentially susceptible to the Müller-Lyer illusion; reflexive movements are reliably but modestly affected by the illusion, whereas voluntary movements show an effect similar to that of perceptual judgments. Results suggest that voluntary saccade programming occurs within a non-retinotopic spatial representation similar to that of visual consciousness, whereas reflexive saccade programming occurs within a representation integrating retinotopic and higher level spatial frames. The effects of the illusion on reflexive saccades are not subject to endogenous control, nor are they modulated by the strength of an exogenous target signal.

General and task-specific frontal lobe recruitment in older adults during executive processes: a fMRI investigation of task-switching

Performance deteriorates when subjects must shift between two different tasks relative to performing either task separately. This switching cost is thought to result from executive processes that are not inherent to the component operations of either task when performed alone. Medial and dorsolateral frontal cortices are theorized to subserve these executive processes. Here we show that larger areas of activation were seen in dorsolateral and medial frontal cortex in both younger and older adults during switching than repeating conditions, confirming the role of these frontal brain regions in executive processes. Younger subjects activated these medial and dorsolateral frontal cortices only when switching between tasks; in contrast, older subjects recruited similar frontal regions while performing the tasks in isolation as well as alternating between them. Older adults recruit medial and dorsolateral frontal areas, and the processes computed by these areas, even when no such demands are intrinsic to the current task conditions. This neural recruitment may be useful in offsetting the declines in cognitive function associated with ageing.

Cognitive neuroscience: origins and promise

Both Freud and Wundt had hoped to base psychology on an understanding of the neural basis of mental events. Their efforts were unsuccessful because the structure and function of the human brain was not available for empirical study at the physiological level. Over the last part of this century, there has been amazing growth and vitality in the field of human brain function. In this paper, we trace critical developments in the fields of cognitive psychology, neuropsychology, and brain imaging related to the development of cognitive neuroscience. Cognitive Neuroscience has established that the decomposition of mental events can be united with an understanding of the mental and emotional computations carried out by the human brain. Cognitive neuroscience has the capability of influencing psychology in diverse areas from how children develop to how adults age; from how humans learn to how we imagine; from volitional control to psychopathologies.

Mental rotation of objects versus hands: neural mechanisms revealed by positron emission tomography

Twelve right-handed men participated in two mental rotation tasks as their regional cerebral blood flow (rCBF) was monitored using positron emission tomography. In one task, participants mentally rotated and compared figures composed of angular branching forms; in the other task, participants mentally rotated and compared drawings of human hands. In both cases, rCBF was compared with a baseline condition that used identical stimuli and required the same comparison, but in which rotation was not required. Mental rotation of branching objects engendered activation in the parietal lobe and Area 19. In contrast, mental rotation of hands engendered activation in the precentral gyrus (M1), superior and inferior parietal lobes, primary visual cortex, insula, and frontal Areas 6 and 9. The results suggest that at least two different mechanisms can be used in mental rotation, one mechanism that recruits processes that prepare motor movements and another mechanism that does not.

Brain mechanisms of cognitive skills

This article examines the anatomy and circuitry of skills that, like reading, calculating, recognizing, or remembering, are common abilities of humans. While the anatomical areas active are unique to each skill there are features common to all tasks. For example, all skills produce activation of a small number of widely separated neural areas that appear necessary to perform the task. These neural areas relate to internal codes that may not be observed by any external behavior nor be reportable by the performer. There is considerable plasticity to the performance of skills. Task components can be given priority through attention, which serves to increase activation of the relevant brain areas. Attention can also cause reactivation of sensory areas driven by input, but usually only after a delay. The threshold for activation for any area may be temporarily reduced by prior activation (priming or practice). Skill components requiring attention tend to cause interference resulting in the dual tasks effects and unified focus of attention described in many cognitive studies. Practice may change the size or number of brain areas involved and alter the pathways used by the skill. By combining cognitive and anatomical analyses, a more general picture of the nature of skill emerges.

Changes in cortical activity during mental rotation. A mapping study using functional MRI

Mental imagery is an important cognitive method for problem solving, and the mental rotation of complex objects, as originally described by Shepard and Metzler (1971), is among the best studied mental imagery tasks. Functional MRI was used to observe focal changes in blood flow in the brains of 10 healthy volunteers performing a mental rotation task. On each trial, subjects viewed a pair of perspective drawings of three-dimensional shapes, mentally rotated one into congruence with the other, and then determined whether the two forms were identical or mirror-images. The control task, which we have called the 'comparison' condition, was identical except that both members of each pair appeared at the same orientation, and hence the same encoding, comparison and decision processes were used but mental rotation was not required. These tasks were interleaved with a baseline 'fixation' condition, in which the subjects viewed a crosshair. Technically adequate studies were obtained in eight of the 10 subjects. Areas of increased signal were identified according to sulcal landmarks and are described in terms of the Brodmann's area (BA) definitions that correspond according to the atlas of Talaraich and Tournoux. When the rotation task was contrasted with the comparison condition, all subjects showed consistent foci of activation in BAs 7a and 7b (sometimes spreading to BA 40): 88% had increased signal in middle frontal gyrus (BA 8) and 75% showed extrastriate activation, including particularly BAs 39 and 19, in a position consistent with area V5/human MT as localized by functional and histological assays. In more than half of the subjects, hand somatosensory cortex (3-1-2) was engaged, and in 50% of subjects there was elevated signal in BA 18. In frontal cortex, activation was above threshold in half the subjects in BAs 9 and/or 46 (dorsolateral prefrontal cortex). Some (four out of eight) subjects also showed signal increases in BAs 44 and/or 46. Premotor cortex (BA 6) was active in half of the subjects during the rotation task. There was little evidence for lateralization of the cortical activity or of engagement of motor cortex. These data are consistent with the hypothesis that mental rotation engages cortical areas involved in tracking moving objects and encoding spatial relations, as well as the more general understanding that mental imagery engages the same, or similar, neural imagery as direct perception.