Forgetting of conditioned fear inhibition

Three experiments assessed retention of conditioned fear and of fear inhibition over long-term retention intervals (35 days in two experiments, 25 days in the third). Although excitatory conditioning was retained well, conditioned inhibition was not. This effect occurred when inhibition was assessed by compounding stimuli on an appetitive baseline and when it was assessed by testing cues on a baseline of unsignalled avoidance responding. Inhibition was also forgotten when the initial conditioning treatment was designed to reduce the role of possible proactive interference processes.     

School neuropsychology

There is an increasing interest among school psychologists in the field of neuropsychology as it relates to children in the educational environment. This article attempts to identify those forces which have led to this increased interest as well as to provide a conceptual framework for recognizing this area of specialty within the profession of school psychology. Potential roles related to levels of training and preparation are discussed.     

Evoked potentials to consonant-vowel syllables

The hypothesis was tested that CV syllables (10 different consonants but the same vowel /?/) would show different evoked potential latencies and amplitudes. Differences were found which were dichotomised between plosives and other consonants. Although one difference between these two groups of consonants is the duration of that consonant, this duration difference did not adequately explain the prolonged evoked potential latencies and the reduced amplitudes for the non-plosives. However, no differences were found within the group of non-plosives, although they varied in consonant duration. It was suggested that N₁ latency and amplitude reflected processing time at an early stage of analysis of both speech and non-speech stimuli. The results show that consunants of long duration are perceived later than plosives, but well before the onset of the vowel.     

Combined stimulus control over time allocation in response-independent schedules

Rats were exposed to concurrent schedules in which reinforcers occurred independently of behavior. In Experiment 1, rats could control time spent in the following conditions: (1) a light, (2) white noise, and (3) the absence of both light and noise. Response-independent reinforcers occurred at the same rate during the light and the noise and at either a higher rate or not at all in the absence of both stimuli. In subsequent tests, the rats spent more time in a light and noise compound than in either light or noise alone after the absence of both stimuli had signaled no reinforcers. When the absence of both stimuli had signaled a higher rate of reinforcement, however, the rats typically spent less time in the compound than in light or noise alone. In Experiment 2, rats could control time spent in the presence of a light and of a buzzer. The reinforcement rate in the light was twice that in the buzzer. In a later test, the rats spent more time in a light and buzzer compound than in the buzzer, but less time in the compound than in the light. The results show that additive summation, suppressive summation, and stimulus averaging of time allocation occur and that response rate differences between training stimuli are not necessary for these phenomena.     

Antecedents to Fechner's law: the astronomers J. Herschel, W. R. Dawes, and N. R. Pogson

The history of the stellar magnitude scale is briefly traced from the second century b.c. until the middle of the nineteenth century. It becomes clear that astronomers formulated "Fechner's Law" by about 1850. While Fechner is credited with the grander view of things, the contention is made that the astronomers John Herschel, W. R. Dawes, and N. R. Pogson have not been given their due by historians of psychology.     

Young children's use of temporal and spatial order information in short-term memory

Encoding and retrieval of temporal and spatial order information was investigated in the free recall and probed recognition performance of 3-, 4-, 5-, and 6-year-olds. In both tasks, three line drawings of familiar objects were presented successively in different spatial locations, so that temporal order was not confounded with spatial order. Subjects of all ages revealed an organization for the stimulus display based on the temporal sequence of presentation. With increasing age, subjects began recall more often with the first item so as to take advantage of this sequential organization. In the probed recognition task, subjects were asked questions requiring the use of temporal or spatial order information. Performance by the older subjects indicated that information about temporal and spatial order could be simultaneously encoded. The results are discussed in terms of a context theory derived from Estes's hierarchical association model.     

Task parameters affecting the efficacy of a visual imagery learning strategy in younger and older children

Second- and sixth-grade children were presented a list of paired associates (concrete nouns) either at a faster (6-second) or a slower (12-second) presentation rate, under either an instruction to generate an interactive image for the pairs or a no strategy, control instruction. The list was composed of two pair types: easy-to-imaginally relate and difficult-to-imaginally relate pairs, as determined from a prior norming study. At the faster presentation rate, 2nd graders were able to benefit from the imagery strategy with easy pairs, but not with difficult pairs. At the slower rate, however, they applied the imagery strategy equally well to both pair types. Older children benefited from the imagery strategy with both pair types at both rates.     

Cross-modal matching and association under sodium amytal

Anatomical and theoretical considerations, as well as experimental findings, have yielded conflicting points of view regarding the abilities of the right hemisphere in man to accomplish cross-modal transfer of information. Auditory—visual cross-modal matching (CMM) and association (CMA) abilities of the left and right hemisphere (LH and RH) were tested, using the Wada intracarotid sodium amytal technique. It was found that the RH performed slightly better on these tasks than the LH. These findings contrast with results of other techniques which indicate that the RH cannot perform CMM and CMA.     

Discrimination of faces by young infants

An experiment was conducted to obtain normative data concerning discrimination between human faces by infants under 6 months of age and to determine the information base required for this performance. Infants were habituated to a specific face and recovery of attention was monitored to a novel face, where one or more features was common to both faces. Results suggested that discrimination between photographs of adult, female faces is possible from 5 weeks of age, with critical information probably lying in the hair-face outline while internal features were relatively unimportant until the 19th week.