Temporal integration in duration and number discrimination

Temporal integration in duration and number discrimination by rats was investigated with the use of a psychophysical choice procedure. A response on one lever ("short" response) following a 1-s white-noise signal was followed by food reinforcement, and a response on the other lever ("long" response) following a 2-s white-noise signal was also followed by food reinforcement. Either response following a signal of one of five intermediate durations was unreinforced. This led to a psychophysical function in which the probability of a long response was related to signal duration in an ogival manner. On 2 test days, a white-noise signal with 5, 6, 7, 8, or 10 segments of either 0.5-s on and 0.5-s off or 1-s on and 1-s off was presented, and a choice response following these signals was unreinforced. The probability of a long response was the same function of a segmented signal and a continuous signal if each segment was considered equivalent to 200 ms. A quantitative fit of a scalar estimation theory suggested that the latencies to initiate temporal integration and to terminate the process are both about 200 ms, and that the same internal accumulation process can be used for counting and timing.     

Simultaneous temporal processing

Seven experiments assessed the ability of rats to process temporal information from two internal clocks simultaneously and independently. In the first six experiments a light stimulus signalled an overall interval between the beginning of a trial and the availability of food reinforcement (e.g., a 50-s fixed interval). During the overall interval a sound stimulus was used to signal shorter intervals that divided the overall interval into equal segments. When there was a fixed temporal relation between the final segment signal and the availability of reinforcement, there was a double-scallop pattern of responding throughout the segmented overall interval; the function relating response rate to time during segment intervals was similar to the function relating response rate to time in unsegmented overall intervals; a change in response rate occurred at the time that a normally presented segment signal was omitted. Taken together, the results indicate that rats timed the overall interval and the segment intervals simultaneously and independently without interference. In Experiment 7 a light stimulus was used on some trials, and a sound stimulus was used on other trials to signal a discrete-trial 50-s peak procedure. When these two signals were presented in compound, there was a leftward shift of the response function, which suggests that rats timed both signals simultaneously. For all of the experiments a scalar timing model with specific stimulus integration rules is used to explain the results. The stimulus integration rule used in the first six experiments, in which there were two signals for the same reinforcement, was to respond if both the segment and the overall interval had exceeded a response threshold. The stimulus integration rule used in Experiment 7, in which there were two signals for different reinforcements, was to respond if the response threshold for either interval had been exceeded.     

Role of spatial location in learning face-name associations

When a face appears at a constant location, formation of a face-name association is facilitated. This facilitation was demonstrated in three experiments. Six subsequent experiments demonstrated that a constant location has its effect primarily because location acts as an additional cue for the name. This conclusion is contrasted with a hypothesis that proposes that a constant location directly strengthens the face-name association. The latter hypothesis does not fit the data as well as thelocation-as-cue hypothesis does.     

ALCOHOL AND DATING RISK FACTORS FOR SEXUAL ASSAULT AMONG COLLEGE WOMEN

American societal norms frequently link alcohol, dating, and sexuality. This cross-sectional study examined the role of alcohol and dating risk factors for sexual assault among a representative sample of female students at a large urban university. Over half of the 1,160 women had experienced some form of sexual assault. Ninety-five percent of these assaults were committed by someone the woman knew and almost half of these assaults involved alcohol consumption by either the man, the woman, or both. Discriminant function analyses indicated that dating, sexual, and misperception experiences and alcohol consumption during these experiences predicted assault group status. Furthermore, alcohol consumption during consensual sex and sexual misperceptions were positively related to alcohol consumption during the sexual assault. The predictors of assault group status were similar for African American and Caucasian women. Theoretical implications are discussed and suggestions are made for combining alcohol and sexual assault prevention programming.     

The Structure of Affect in a Non-Western Culture: Evidence for Cross-Cultural Comparability

We investigated the structure of affect in the Filipino culture and compared our results to those in Western studies. Four samples of students (ns = 397 to 530) rated their mood for today, the past week, or in general, using near-comprehensive sets of Filipino mood adjectives. Results of exploratory and confirmatory factor analyses supported a hierarchical model of affect and the cross-cultural comparability of self-report mood dimensions (i.e., higher-order Positive and Negative Affect, plus specific affects corresponding to hypothesized universal or basic emotions). The results were more consistent with biological theories of affect than a strong social constructivist perspective.     

Emotional and Behavioural Difficulties in Schools: Consideration of Relationships Between Theory and Practice

Current research has found that students who experience emotional and behavioural difficulties (EBDs) in school are not identified early, their behaviours (and causes) are often misrepresented, and they may not receive appropriate intervention. In this paper we review current theories (and their shortcomings) on the identification and recommended actions for students who experience EBDs, acknowledging the importance of teachers' initial identification (as schools are the social arena within which most students who experience EBDs are first identified). We suggest that teachers' identification may not be informed by the full range of theories and explanations for EBDs and that they often disregard the emotional and relational aspect of EBDs which focus on individual students and fail to recognize the social context in which the students operate. These suggestions were supported in a questionnaire-based study. Teachers' identification of EBDs coincides with predominant theoretical explanations based upon an individual's inability to fit into society, seeing EBDs as a product rather than social process. Such a situation may encourage instability in classrooms and may not allow for adequate intervention for EBDs.     

HUMAN MODELS OF ANIMAL BEHAVIOR

Abstract— Similarities between the behavior of humans and other animals in analogous tasks suggest that similar cognitive processes are involved. Human studies provide an efficient way to collect data with low variability, and animal studies provide a way to collect a large amount of data under controlled conditions, study a wide range of manipulations, limit the range of plausible explanations, and develop explanations in terms of brain mechanisms. Examples are taken from studies of liming that used similar procedures for humans and other animals.