THE SIMILARITY OF BRAIN ACTIVITY ASSOCIATED WITH TRUE AND FALSE RECOGNITION MEMORY DEPENDS ON TEST FORMAT

Abstract— Event-related potentials (ERPs) were compared for correct recognitions of previously presented words and false recognitions of associatively related, nonpresented words (lures). When the test items were presented blocked by test type (old, new, lure), waveforms for old and lure items were different, especially at frontal and left parietal electrode sites, consistent with previous positron emission tomography (PET) data (Schacter, Reiman, et. al., 1996). When the test format randomly intermixed the types of items, waveforms for old and lure items were more similar. We suggest that test format affects the type of processing subjects engage in, consistent with expectations from the source-monitoring framework (Johnson, Hashtroudi, & Lindsay, 1993). These results also indicate that brain activity as assessed by neuroimaging designs requiring blocked presentation of trials (e g, PET) do not necessarily reflect the brain activity that occurs in cognitive-behavioral paradigms, in which types of test trials are typically intermixed.     

Social value orientations and negotiator outcomes

Social value orientations (SVOs) are known to influence individual behaviour in outcome interdependent settings. By extending these findings to negotiation, this research investigates the relationship between own and partners' SVOs, negotiator strategies and outcomes. Results showed that cooperators, competitors and individualists could be distinguished in terms of initial demands and concessions. Competitors made higher initial demands and larger concessions than individualists or cooperators, suggesting that their ability to maximize outcome differences rests on whether structural features are congruent with this goal. The principal finding of this research was the demonstration that own and partners' SVO interact to determine outcomes. Results showed that the three SVO groups differed in terms of context sensitivity: competitor outcomes were invariant across partners; individualists achieved poor outcomes in negotiations with cooperators and, reciprocally, cooperators attained high outcomes in negotiations with individualists. Additionally, individualist outcomes worsened in their last negotiation, while those of cooperators differed as a function of role and partner's SVO. These results suggest that although the information used by individualists and cooperators differs, for both groups the cognitive representation of negotiations is a further factor influencing their outcomes.     

Moments in time: metacognition, trust, and outcomes in dyadic negotiations

This research tested the relationships between turning points, cognitive and affective trust, and negotiation outcomes. After completing a simulated negotiation, participants identified turning points from videotape. Turning points were then classified as substantive (interest, offer), characterization (positive, negative), or procedural (positive, negative). Prenegotiation affective trust predicted subsequent turning points, whereas prenegotiation cognitive trust did not, suggesting that different cues influence the two types of trust. Postnegotiation cognitive trust was increased by the occurrence of interest, positive characterization, and positive procedural turning points and decreased by negative characterization turning points. Affective trust was increased by positive procedural turning points. Finally, interest turning points resulted in higher joint outcomes, whereas negative characterization turning points resulted in lower joint outcomes. We conclude that there are two paths to building trust and increasing joint gain, one through insight and one through signaling good faith intentions.     

Spatial learning in rats is impaired by microinfusions of protein kinase C-gamma antisense oligodeoxynucleotide within the nucleus accumbens

The nucleus accumbens (NAcc) has been shown to play a role in motor and spatial learning. Protein kinase C (PKC) has been implicated in the mechanisms of initiation and maintenance of long-term potentiation that is thought to be involved in the storage of long-term memory. In the present study, the importance of de novo synthesis of PKC-gamma within the NAcc in the acquisition and retention of spatial discrimination learning was assessed using an antisense knockdown approach. Separate groups of Long-Evans rats were exposed to acute microinfusions (6microg/microl) of PKC-gamma antisense oligodeoxynucleotide (AS-ODN), control oligodeoxynucleotide (C-ODN) or vehicle into the NAcc at 24 and 3h before each training session. Behavioral findings showed that the blockade of NAcc-PKC-gamma translation caused impairments in the early phase of learning and retention of spatial information. Biochemical experiments showed that PKC-gamma expression was reduced and Ca(2+)/phospholipid-dependent protein kinase C (PKC) activity was blocked significantly in the AS-ODN-treated rats in comparison with control rats. The present findings suggest that NAcc-PKC-gamma plays a role during the early acquisition of spatial learning. Also, retention test results suggest that NAcc-PKC-gamma may be working as an intermediate factor involved in the onset of molecular mechanisms necessary for spatial memory consolidation within the NAcc.     

The positive and negative effects of anger on dispute resolution: evidence from electronically mediated disputes

Scholars have argued that anger expressed by participants in mediation is counterproductive; yet, there is also reason to believe that expressions of anger can be productive. The authors tested these competing theories of emotion by using data from online mediation. Results show that expression of anger lowers the resolution rate in mediation and that this effect occurs in part because expressing anger generates an angry response by the other party. However, when respondents are especially vulnerable, expressions of anger by the filer do not hinder settlement. The authors also examined precursors to anger, such as value of dispute and reputation, and the degree to which a focus on dispute resolution is reciprocated.     

Remembering chosen and assigned options

Recent studies have shown systematic choice-supportive memory for past choices, wherein people tend to overattribute positive features to options they chose and negative features to unchosen options (Mather & Johnson, 2000, Mather, Shafir, & Johnson, 2000). In contrast, the present experiments showed no choice-supportive memory bias for assigned options. Rather than having a general motivation to recall the chosen or the assigned option in a more positive light, people appear to be influenced by heuristics that vary with context: In recalling past choices, people expect the chosen option to contain more positive and fewer negative features than do its competitors. In recalling past assignments, in contrast, people expect the assigned option to be remembered better than the unassigned alternatives. This vividness heuristic leads to systematic misattribution of new features to unassigned alternatives, but not in a manner supportive of the assigned option. Some implications of these findings are discussed.     

Beyond arousal and valence: The importance of the biological versus social relevance of emotional stimuli

The present study addressed the hypothesis that emotional stimuli relevant to survival or reproduction (biologically emotional stimuli) automatically affect cognitive processing (e.g., attention, memory), while those relevant to social life (socially emotional stimuli) require elaborative processing to modulate attention and memory. Results of our behavioral studies showed that (1) biologically emotional images hold attention more strongly than do socially emotional images, (2) memory for biologically emotional images was enhanced even with limited cognitive resources, but (3) memory for socially emotional images was enhanced only when people had sufficient cognitive resources at encoding. Neither images’ subjective arousal nor their valence modulated these patterns. A subsequent functional magnetic resonance imaging study revealed that biologically emotional images induced stronger activity in the visual cortex and greater functional connectivity between the amygdala and visual cortex than did socially emotional images. These results suggest that the interconnection between the amygdala and visual cortex supports enhanced attention allocation to biological stimuli. In contrast, socially emotional images evoked greater activity in the medial prefrontal cortex (MPFC) and yielded stronger functional connectivity between the amygdala and MPFC than did biological images. Thus, it appears that emotional processing of social stimuli involves elaborative processing requiring frontal lobe activity.     

Books Received

Leg-to-body ratio (LBR) is one of the morphological traits that influences a person's attractiveness. To date, studies confirming that hypothesis have been conducted mainly in Western cultures. They have shown that the average or slightly higher-than-the-average LBR is perceived to be attractive in women. In the case of men, results were more ambiguous; however generally shorter or similar LBRs compared to females were attractive. Here, data on LBR preferences of a traditional, semi-nomad ethnic group (i.e., the Himba of northern Namibia, n = 81) are reported. Also in Himba people LBR influences a person's attractiveness. Similar to Western societies, extremely high and low LBRs were unattractive. However, contrary to previous findings, Himba preferred women of relatively low LBR and men of relatively high LBR.