Preserved re-experience of discrete emotions: Amnesia and executive function

Amnesic patients can re-experience emotions elicited by forgotten events, suggesting that brain systems for episodic and emotional memory are independent. However, the range of such emotional memories remains under-investigated (most studies employing just positive–negative emotion dyads), and executive function may also play a role in the re-experience of emotions. This is the first investigation of the intensity of the emotional re-experience of a range of discrete emotions (anger, fear, sadness, and happiness) for a group of amnesic patients. Twenty Korsakoff syndrome (KS) patients and 20 neurologically normal controls listened to four novel emotional vignettes selectively eliciting the four basic emotions. Emotional experience was measured using pen-and-paper Visual Analogue Mood Scales and episodic memory using verbal recollections. After 30 min, the recollection of stories was severely impaired for the patient group, but the emotional re-experience was no different from that of controls. Notably, there was no relationship between episodic recall and the intensity of the four emotions, such that even profoundly amnesic patients reported moderate levels of the target emotion. Exploratory analyses revealed negative correlations between the intensity of basic emotions and executive functions (e.g., cognitive flexibility and response inhibition) for controls but not patients. The results suggest that discrete emotions can be re-experienced independently of episodic memory, and that the re-experience of certain discrete emotions appears to be dampened by executive control. KS patients with absent or mild cognitive symptoms should benefit from emotion-regulation interventions aimed at reducing the recognized affective burden associated with their episodic memory deficit.     

Meerkats (<Emphasis Type="Italic">Suricata suricatta</Emphasis>) fail to prosocially donate food in an experimental set-up

Although humans are usually believed to be prosocial, the evolutionary origins of prosociality are largely debated. One hypothesis is that cooperative breeding has been one major precursor to the emergence of prosociality. In vertebrates, however, experimental evidence of prosociality has been mainly gathered in non-human primates. In this study, we tested the cooperative breeding hypothesis in cooperative breeding meerkats (Suricata suricatta). In particular, we tested whether meerkats take into account partners’ benefits when distributing food rewards. Nine individuals were presented with two platforms baited with different food distributions (providing food to themselves, to a partner or both). In all conditions, the decision to operate the apparatus was based on the presence of food on the subject’s side, and not on the possible benefits to partners. Despite being cooperative breeders, meerkats in this study failed to be prosocial, suggesting that prosociality in this species may be limited to specific contexts.     

Perceived in‐group threat as a factor moderating the influence of in‐group norms on discrimination against foreigners

Within the framework of an intergroup relations paradigm, three studies analysed the role of in‐group threat in intergroup discrimination and the influence of in‐group norms on intergroup discrimination. The first study showed that perceived socio‐economic threat underlies Swiss nationals' prejudice and discrimination toward foreigners in Switzerland. The second and third studies experimentally tested the hypotheses, first, that variations in perception of in‐group threat will produce change in initial discrimination, and, second, that the influence of an in‐group norm (pro‐ vs. anti‐ discriminatory) is moderated by the perception of in‐group threat. In support of these predictions, results of both studies indicated that discrimination was reduced when perceived in‐group threat was low. However, the anti‐discriminatory in‐group norm reduced discrimination only when perceived in‐group threat was low. No influence was observed for the pro‐discriminatory in‐group norm. Copyright © 2004 John Wiley & Sons, Ltd.     

The role of the nucleus accumbens in knowing when to respond

While knowing what to expect is important, it is equally important to know when to expect it and to respond accordingly. This is apparent even in simple Pavlovian training situations in which animals learn to respond more strongly closer to reward delivery. Here we report that the nucleus accumbens core, an area well-positioned to represent information about the timing of impending rewards, plays a critical role in this timing function.     

Simultaneous motion perception along multiple attributes: A new class of stimuli

This paper describes a novel class of visual stimuli that have been created to study stroboscopic motion perception along multiple attributes. The stimuli are composed of discrete elements, each of which can be characterized by an arbitrary number of attributes (color, luminance, spatial frequency, binocular disparity, etc.). There are two choices for the spatiotemporal arrangement of each attribute: to elicit either unambiguous (unidirectional) motion perception or ambiguous (bidirectional) motion perception. This affords the unique ability to elicit simultaneous motion perception in opposing directions from identical stimuli. The prevailing direction depends on the relative strength of the attributes’ contribution to the motion mechanisms (for short frame duration), or on the particular attribute being attended to (for long frame duration). Thus, this class of stimuli opens up the possibility of isolating specific motion mechanisms in the visual system.