The effect of temporal constraints on the value of money and other commodities

The value of hypothetical rewards of various delays and durations, consisting of money or other commodities, such as automobile use and vacations, was measured by the psychophysical up-down staircase method using an amount of unrestricted immediate money as the titrated variable. A model of temporal discounting based on implied constraints on anticipated consumption rate described the data. Further explicit constraints on consumption produced predictable deviations from the model. The concept that consumption is normally constrained together with time discounting may also explain the interaction between amount and delay of monetary reward in determining value and may provide the basis for a theory of addiction based on learning to increase consumption rate.     

Looking for answers: eye movements in non-visual cognitive tasks

It is not known why people move their eyes when engaged in non-visual cognition. The current study tested the hypothesis that differences in saccadic eye movement rate (EMR) during non-visual cognitive tasks reflect different requirements for searching long-term memory. Participants performed non-visual tasks requiring relatively low or high long-term memory retrieval while eye movements were recorded. In three experiments, EMR was substantially lower for low-retrieval than for high-retrieval tasks, including in an eyes closed condition in Experiment 3. Neither visual imagery nor between-task difficulty was related to EMR, although there was some evidence for a minor effect of within-task difficulty. Comparison of task-related EMRs to EMR during a no-task waiting period suggests that eye movements may be suppressed or activated depending on task requirements. We discuss a number of possible interpretations of saccadic eye movements during non-visual cognition and propose an evolutionary model that links these eye movements to memory search through an elaboration of circuitry involved in visual perception.     

Effects of age on contextually mediated associations in paired associate learning

Older and young adults learned single-function lists of paired associates with no contextual overlap (e.g., J-K, L-M) and double-function lists of paired associates consisting of chains of pairs (e.g., A-B, B-C). Although young adults outperformed older adults on both pair types, there was a robust Pair Type x Age interaction. Evidence from intrusion analyses shows that older adults performed better than would be expected on the contextually overlapping double-function pairs because they were less subject to response competition for the double-function pairs. Young adults made a larger proportion of backward and remote intrusions to double-function probes than did older adults. Thus, group differences in both correct-recall probabilities and intrusion analysis suggest that backward and transitive associations are sensitive to aging. The results are discussed within the theoretical framework of the temporal context model and the hypothesis that older adults are impaired at forming new item-context associations.     

Chronic Auditory Agnosia Following Landau-Kleffner Syndrome: A 23 Year Outcome Study

We report a 27-year-old woman with chronic auditory agnosia following Landau-Kleffner Syndrome (LKS) diagnosed at age 4 1/2 . She grew up in the hearing/speaking community with some exposure to manually coded English and American Sign Language (ASL). Manually coded (signed) English is her preferred mode of communication. Comprehension and production of spoken language remain severely compromised. Disruptions in auditory processing can be observed in tests of pitch and duration, suggesting that her disorder is not specific to language. Linguistic analysis of signed, spoken, and written English indicates her language system is intact but compromised because of impoverished input during the critical period for acquisition of spoken phonology. Specifically, although her sign language phonology is intact, spoken language phonology is markedly impaired. We argue that deprivation of auditory input during a period critical for the development of a phonological grammar and auditory–verbal short-term memory has limited her lexical and syntactic development in specific ways.