Chinese patients' response to doctor-patient relationship stimuli: evidence from an event-related potential study

Background

With improvements in medical technology, the doctor–patient relationship should be further improved. However, disputes between doctors and patients have increased, with the two groups frequently hurting each other. Therefore, we sought to explore the perception of Chinese patients regarding the stimuli of doctor–patient relationships with different valence.

Methods

We used event-related potential (ERP) to explore the brain electrical activity of 19 undergraduate participants who had a clinical experience in the previous 6 months where they perceived negative, neutral, and positive doctor–patient relationships. The ERPs were recorded, and the early ERP components (P2) and late positive potential (LPP) were measured.

Results

Compared with the stimuli of negative doctor–patient relationships, those of positive doctor–patient relationships would attract more attention and have larger P2 amplitude; LPP was larger for the stimuli of negative doctor–patient relationships than neutral ones in the 500–800 ms, while in the 1100–1500 ms, the stimuli of neutral doctor–patient relationships elicited larger LPP amplitude than positive ones.

Conclusion

Patients paid more attention to the stimuli of positive doctor–patient relationships because they expected to have the same positive relationship. Although threatening elements in negative doctor–patient relationships would catch patients’ attention and make them have implicit emotional regulation, neutral stimuli with poker-faced doctors would cause lasting attention. These results illustrate the patients’ real perception of the different valence of doctor–patient relationship stimuli.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40359-022-00961-y.

What Is It Like to Be a Bass? Red Herrings, Fish Pain and the Study of Animal Sentience

Debates around fishes' ability to feel pain concern sentience: do reactions to tissue damage indicate evaluative consciousness (conscious affect), or mere nociception? Thanks to Braithwaite's discovery of trout nociceptors, and concerns that current practices could compromise welfare in countless fish, this issue's importance is beyond dispute. However, nociceptors are merely necessary, not sufficient, for true pain, and many measures held to indicate sentience have the same problem. The question of whether fish feel pain - or indeed anything at all - therefore stimulates sometimes polarized debate. Here, we try to bridge the divide. After reviewing key consciousness concepts, we identify "red herring" measures that should not be used to infer sentience because also present in non-sentient organisms, notably those lacking nervous systems, like plants and protozoa (P); spines disconnected from brains (S); decerebrate mammals and birds (D); and humans in unaware states (U). These "S.P.U.D. subjects" can show approach/withdrawal; react with apparent emotion; change their reactivity with food deprivation or analgesia; discriminate between stimuli; display Pavlovian learning, including some forms of trace conditioning; and even learn simple instrumental responses. Consequently, none of these responses are good indicators of sentience. Potentially more valid are aspects of working memory, operant conditioning, the self-report of state, and forms of higher order cognition. We suggest new experiments on humans to test these hypotheses, as well as modifications to tests for "mental time travel" and self-awareness (e.g., mirror self-recognition) that could allow these to now probe sentience (since currently they reflect perceptual rather than evaluative, affective aspects of consciousness). Because "bullet-proof" neurological and behavioral indicators of sentience are thus still lacking, agnosticism about fish sentience remains widespread. To end, we address how to balance such doubts with welfare protection, discussing concerns raised by key skeptics in this debate. Overall, we celebrate the rigorous evidential standards required by those unconvinced that fish are sentient; laud the compassion and ethical rigor shown by those advocating for welfare protections; and seek to show how precautionary principles still support protecting fish from physical harm.

On the Automatic Nature of Threat: Physiological and Evaluative Reactions to Survival-Threats Outside Conscious Perception

A neural architecture that preferentially processes immediate survival threats relative to other negatively and positively valenced stimuli presumably evolved to facilitate survival. The empirical literature on threat superiority, however, has suffered two problems: methodologically distinguishing threatening stimuli from negative stimuli and differentiating whether responses are sped and strengthened by threat superiority or delayed and diminished by conscious processing of nonthreatening stimuli. We addressed both problems in three within-subject studies that compared responses to empirically validated sets of threating, negative, positive, and neutral stimuli, and isolated threat superiority from the opposing effect of conscious attention by presenting stimuli outside conscious perception. Consistent with threat superiority, threatening stimuli elicited stronger skin-conductance (Study 1), startle-eyeblink (Study 2), and more negative downstream evaluative responses (Study 3) relative to the undifferentiated responses to negative, positive, and neutral stimuli.

Supplementary Information

The online version contains supplementary material available at 10.1007/s42761-021-00090-6.

Model Gender Interacts With Expressed Emotion to Enhance Startle: Angry Male and Happy Female Faces Produce the Greatest Potentiation

Several studies have implied gender differences in startle reaction to emotional facial expressions. However, few studies have been designed to investigate the difference between responding to emotional female vs. male faces, nor gender differences in responses. The present experiment investigated startle EMG responses to a startle probe while viewing pictures of neutral, happy, angry, fearful, and sad facial expressions presented by female and male models. Participants were divided into female and male groups. Results showed that emotional facial expressions interact with model gender to produce startle potentiation to a probe: greater responses were found while viewing angry expressions by male models, and while viewing happy faces by female models. There were no differences in responses between male and female participants. We argue that these findings underline theimportance of controlling for model gender in research using facial expressions as stimuli.

Dissociating the physiological components of unconscious emotional responses

Conscious emotional processing is characterized by a coordinated set of responses across multiple physiological systems. Although emotional stimuli can evoke certain physiological responses even when they are suppressed from awareness, it is not known whether unconscious emotional responses comprise a similar constellation or are confined to specific systems. To compare physiological responses to emotional stimuli with and without awareness, we measured a range of responses while participants viewed positive, negative and neutral images that were accompanied by noise bursts to elicit startle reflexes. We measured four responses simultaneously - skin conductance and heart rate changes in response to the images themselves; and startle eye-blink and post-auricular reflexes in response to the noise bursts that occurred during image presentation. For half of the participants, the images were masked from awareness using continuous flash suppression. The aware group showed the expected pattern of response across physiological systems: emotional images (regardless of valence) evoked larger skin conductance responses (SCRs) and greater heart rate deceleration than neutral images, negative images enhanced eye-blink reflexes and positive images enhanced post-auricular reflexes. In contrast, we found a striking dissociation between measures for the unaware group: typical modulation of SCRs and post-auricular reflexes, but no modulation of heart rate deceleration or eye-blink reflexes. Our findings suggest that although some physiological systems respond to emotional stimuli presented outside of awareness, conscious emotional processing may be characterized by a broad and coordinated set of responses across systems.

In Harm’s Way: On Preferential Response to Threatening Stimuli

Given the evolutionary significance of survival, the mind might be particularly sensitive (in terms of strength and speed of reaction) to stimuli that pose an immediate threat to physical harm. To rectify limitations in past research, we pilot-tested stimuli to obtain images that are threatening, nonthreatening-negative, positive, or neutral. Three studies revealed that participants (a) were faster to detect a threatening than nonthreatening-negative image when each was embedded among positive or neutral images, (b) oriented their initial gaze more frequently toward threatening than nonthreatening-negative, positive, or neutral images, and (c) evidenced larger startle-eyeblinks to threatening than to nonthreatening-negative, positive, or neutral images. Social-psychological implications for the mind’s sensitivity to threat are discussed.

In Your Face: Startle to Emotional Facial Expressions Depends on Face Direction

Although faces are often included in the broad category of emotional visual stimuli, the affective impact of different facial expressions is not well documented. The present experiment investigated startle electromyographic responses to pictures of neutral, happy, angry, and fearful facial expressions, with a frontal face direction (directed) and at a 45° angle to the left (averted). Results showed that emotional facial expressions interact with face direction to produce startle potentiation: Greater responses were found for angry expressions, compared with fear and neutrality, with directed faces. When faces were averted, fear and neutrality produced larger responses compared with anger and happiness. These results are in line with the notion that startle is potentiated to stimuli signaling threat. That is, a forward directed angry face may signal a threat toward the observer, and a fearful face directed to the side may signal a possible threat in the environment.

The amygdala mediates the emotional modulation of threat-elicited skin conductance response

The ability to respond adaptively to threats in a changing environment is an important emotional function. The amygdala is a critical component of the neural circuit that mediates many emotion-related processes, and thus likely plays an important role in modulating the peripheral emotional response to threat. However, prior research has largely focused on the amygdala's response to stimuli that signal impending threat, giving less attention to the amygdala's response to the threat itself. From a functional perspective, however, it is the response to the threat itself that is most biologically relevant. Thus, understanding the factors that influence the amygdala's response to threat is critical for a complete understanding of adaptive emotional processes. Therefore, we used functional MRI to investigate factors (i.e., valence and arousal of co-occurring visual stimuli) that influence the amygdala's response to threat (loud white noise). We also assessed whether changes in amygdala activity varied with the peripheral expression of emotion (indexed via skin conductance response; SCR). The results showed that threat-elicited amygdala activation varied with the arousal, not valence, of emotional images. More specifically, threat-elicited amygdala activation was larger to the threat when presented during high-arousal (i.e., negative and positive) versus low-arousal (i.e., neutral) images. Further, the threat-elicited amygdala response was positively correlated with threat-elicited SCR. These findings indicate the amygdala's response to threat is modified by the nature (e.g., arousal) of other stimuli in the environment. In turn, the amygdala appears to mediate important aspects of the peripheral emotional response to threat.

Gender of the expresser moderates the effect of emotional faces on the startle reflex

It has been suggested that the impact of emotional expressions on the startle reflex is influenced by the intention communicated by the expression (e.g., the intention to attack). However, we propose that the meaning of an emotional expression is not only based on the intention, but is also influenced by characteristics of the expresser such as gender: since men are typically seen as more dominant than women, anger expressed by men should be perceived as particularly threatening, thus amplifying the startle response. We compared the influence of anger, fear and neutral expressions shown by men and women on the startle reaction. Startle reactions were measured using electromyography. As predicted, we found stronger startle reactions after the presentation of anger expressed by men compared to fearful and neutral expressions shown by men. For female expressers, the startle response was not affected by expression type.