The prefrontal cortex in sleep

Experimental data indicate a role for the prefrontal cortex in mediating normal sleep physiology, dreaming and sleep-deprivation phenomena. During nonrandom-eye-movement (NREM) sleep, frontal cortical activity is characterized by the highest voltage and the slowest brain waves compared to other cortical regions. The differences between the self-awareness experienced in waking and its diminution in dreaming can be explained by deactivation of the dorsolateral prefrontal cortex during REM sleep. Here, we propose that this deactivation results from a direct inhibition of the dorsolateral prefrontal cortical neurons by acetylcholine, the release of which is enhanced during REM sleep. Sleep deprivation influences frontal executive functions in particular, which further emphasizes the sensitivity of the prefrontal cortex to sleep.     

Mapping Attitude Formation as a Function of Information Input: Online Processing Models of Attitude Formation

Consistent with calls for a dynamical social psychology (Jacoby et al., 1987; Nowak, Lewenstein, & Vallacher, 1994), attitude formation was studied using a recently developed, computer‐based simulation technique termed Higher Order Cognitive Tracing (see Jacoby et al., 1994). Participants’ attitudes toward 12 different products in 3 product categories were investigated as a function of incremental information input. As opposed to traditional memory‐based models of attitude formation, the study explored online processing models. Results indicate that the impact of information tends to decrease the later in the sequence that information is accessed. In addition, new information that is affectively inconsistent with prior information tends to have a greater impact on attitudes than information that is affectively redundant. This effect is more pronounced earlier rather than later in the sequence of information acquisition. Implications and suggestions for future research are discussed.     

Memory conformity: can eyewitnesses influence each other's memories for an event?

The current study investigated memory conformity effects between individuals who witness and then discuss a criminal event, employing a novel procedure whereby each member of a dyad watches a different video of the same event. Each video contained unique items that were thus seen only by one witness. Dyads in one condition were encouraged to discuss the event before each witness (individually) performed a recall test, while in a control condition dyads were not allowed to discuss the event prior to recall. A significant proportion (71%) of witnesses who had discussed the event went on to mistakenly recall items acquired during the discussion. There were no age‐related differences in susceptibility to these memory conformity effects in younger (18–30 years) as compared to older (60–80 years) participants. Possible social and cognitive mechanisms underlying the distortions of memory due to conformity are discussed. Copyright © 2003 John Wiley & Sons, Ltd.     

Temporal Contiguity and Contingency Judgments: A Pavlovian Analogue

The two experiments reported examine the role of temporal contiguity on judgments of contingency in a human analogue of the Pavlovian task. The data show that the effect of the actual delay on contingency judgment depends on the observer's expectation regarding the delay. For a fixed contingency between the cue and the outcome, ratings of the contingency are higher when the actual delay is congruent with the observer's expectation than when it is incongruent. We argue that our data can be understood within the context of the temporal coding hypothesis.     

Internet use and social support in women with breast cancer.

Many Web sites offer information to breast cancer patients, who are increasingly using these sites. The authors investigated the potential psychological benefits of Internet use for medical information by breast cancer patients. Of the 251 women approached, 188 were successfully interviewed (74.9%). Forty-two percent used the Internet for medical information related to breast health issues and did so for an average of 0.80 hr per week. The Interpersonal Support Evaluation List and the UCLA Loneliness Scale, with results controlled for covariates, showed that Internet use for breast health issues was associated with greater social support and less loneliness than Internet use for other purposes or nonuse. Breast cancer patients may obtain these psychological benefits with only a minimal weekly time commitment.