A list-length constraint on incidental item-to-item associations

We investigated the possibility that item-to-item associations form between items concurrently included in a capacity-limited region of working memory, but not outside of that region. Many studies indicate a central capacity limit of 3 to 5 items (e.g., Cowan, 2001). Participants received lists of 3, 6, or 9 words along with an orienting task, selecting the most interesting word from each list. Consistent with expectations, a subsequent, unexpected test showed that memory of whether two words came from the same list or not was superior for 3-word lists compared to 6- and 9-word lists, which did not differ. This effect occurred even though the separation between the list positions of the two probe words was controlled across list lengths. The study demonstrates a source of implicit learning that depends upon a limited-capacity working memory faculty, a finding that should inspire further research on the function of working memory in long-term learning

Estimating working memory capacity for lists of nonverbal sounds

Working memory (WM) capacity limit has been extensively studied in the domains of visual and verbal stimuli. Previous studies have suggested a fixed WM capacity of typically about 3 or 4 items, based on the number of items in working memory reaching a plateau after several items as the set size increases. However, the fixed WM capacity estimate appears to rely on categorical information in the stimulus set (Olsson & Poom, 2005). We designed a series of experiments to investigate nonverbal auditory WM capacity and its dependence on categorical information. Experiments 1 and 2 used simple tones and revealed capacity limit of up to 2 tones following a 6-s retention interval. Importantly, performance was significantly higher at set sizes 2, 3, and 4 when the frequency difference between target and test tones was relatively large. In Experiment 3, we added categorical information to the simple tones, and the effect of tone change magnitude decreased. Maximal capacity for each individual was just over 3 sounds, in the range of typical visual procedures. We propose that two types of information, categorical and detailed acoustic information, are kept in WM, and that categorical information is critical for high WM performance

Modeling working memory: An interference model of complex span

This article introduces a new computational model for the complex-span task, the most popular task for studying working memory. SOB-CS is a two-layer neural network that associates distributed item representations with distributed, overlapping position markers. Memory capacity limits are explained by interference from a superposition of associations. Concurrent processing interferes with memory through involuntary encoding of distractors. Free time in-between distractors is used to remove irrelevant representations, thereby reducing interference. The model accounts for benchmark findings in four areas: (1) effects of processing pace, processing difficulty, and number of processing steps; (2) effects of serial position and error patterns; (3) effects of different kinds of item-distractor similarity; and (4) correlations between span tasks. The model makes several new predictions in these areas, which were confirmed experimentally

Dose-related effects of alcohol on cognitive functioning

We assessed the suitability of six applied tests of cognitive functioning to provide a single marker for dose-related alcohol intoxication. Numerous studies have demonstrated that alcohol has a deleterious effect on specific areas of cognitive processing but few have compared the effects of alcohol across a wide range of different cognitive processes. Adult participants (N = 56, 32 males, 24 females aged 18–45 years) were randomized to control or alcohol treatments within a mixed design experiment involving multiple-dosages at approximately one hour intervals (attained mean blood alcohol concentrations (BACs) of 0.00, 0.048, 0.082 and 0.10%), employing a battery of six psychometric tests; the Useful Field of View test (UFOV; processing speed together with directed attention); the Self-Ordered Pointing Task (SOPT; working memory); Inspection Time (IT; speed of processing independent from motor responding); the Traveling Salesperson Problem (TSP; strategic optimization); the Sustained Attention to Response Task (SART; vigilance, response inhibition and psychomotor function); and the Trail-Making Test(TMT; cognitive flexibility and psychomotor function). Results demonstrated that impairment is not uniform across different domains of cognitive processing and that both the size of the alcohol effect and the magnitude of effect change across different dose levels are quantitatively different for different cognitive processes. Only IT met the criteria for a marker for wide-spread application: reliable dose-related decline in a basic process as a function of rising BAC level and easy to use non-invasive task properties.Mathew J. Dry, Nicholas R. Burns, Ted Nettelbeck, Aaron L. Farquharson and Jason M. Whit

Effects of Exposure to Alcohol-Related Cues On Racial Discrimination

Prior research has shown that exposure to alcohol‐related images exacerbates expression of implicit racial biases, and that brief exposure to alcohol‐related words increases aggressive responses. However, the potential for alcohol cue exposure to elicit differential aggression against a Black (outgroup) relative to a White (ingroup) target—that is, racial discrimination—has never been investigated. Here, we found that White participants (N = 92) exposed to alcohol‐related words made harsher judgments of a Black experimenter who had frustrated them than participants who were exposed to nonalcohol words. These findings suggest that exposure to alcohol cues increases discriminatory behaviors toward Blacks

Effects of Exposure to Alcohol-Related Cues On Racial Prejudice

Prior research (Stepanova, Bartholow, Saults, & Friedman, 2012) indicates that exposure to alcohol-related cues increases expressions of racial biases. This study investigated whether such effects can be replicated with other tasks assessing racial bias and whether they stem from stereotyping or prejudice. In two experiments participants (N1 = 118; N2 = 152) were exposed to either alcohol-related or neutral advertisements, and then completed a race-priming lexical decision task (LDT, Wittenbrink, Judd, and Park, 1997). Experiment 1 provided weak evidence that exposure to alcohol cues decreases positive attitudes toward Blacks, which was not confirmed in a high-powered replication (Experiment 2). Our findings suggest a short-lived nature (if any) of alcohol priming effects on racial bias when measured by the primed LDT