A comparison of the environments of day care centers and group day care homes for 3 year olds

Caregiver-child interaction and social participation were compared in community-based day care centers and group day care homes for three year olds. Use of group day care homes made it possible to control for group size and adult-child ratio. Day care homes were found to be more structured in terms of curriculum, and more flexible in terms of overall schedule and social-emotional climate. Adult child interaction was of higher quality during structured periods in day care homes. Social participation was of higher quality in day care homes. The adult-child interaction in both types of day care was impersonal and neutral in affective tone.     

Effects of d-amphetamine, cocaine, and phencyclidine on the acquisition of response sequences with and without stimulus fading.

In each of three components of a multiple schedule, monkeys were required to emit a different sequence of four responses in a predetermined order on four levers. Sequence completions produced food on a fixed-ratio schedule. Errors produced a brief timeout. One component of the multiple schedule was a repeated-acquisition task where the four-response sequence changed each session (learning). The second component of the multiple schedule was also a repeated-acquisition task, but acquisition was supported through the use of a stimulus-fading procedure (faded learning). In a third component of the multiple schedule, the sequence of responses remained the same from session to session (performance). At higher doses, d-amphetamine, cocaine, and phencyclidine decreased the overall rate of responding and increased the percent errors in all three components. At lower doses, however, the three drugs produced selective effects on errors. Errors were increased in the learning component at lower doses than those required to disrupt the behavior in the faded-learning component. The performance component tended to be the least sensitive to disruptive drug effects. The data are consistent with the view that stimulus fading can modulate the effects of drugs on acquisition.     

Autonomic and behavioral effects of dextroamphetamine and placebo in normal and hyperactive prepubertal boys

The hypothesis is tested that the response to dextroamphetamine in terms of activity, attention, impulsivity, and autonomic activity is similar in normal (N) and hyperactive (H) children. Fourteen N and 15 H boys had skin conductance (SC), heart rate (HR), and finger temperature (ST) recorded during rest, presentation of eight 75- dB tones, and a reaction time (RT) procedure on three occasions: off drug (Day 1) and after ingestion (double-blind) of placebo and of .5 mg/kg dextroamphetamine. Both N and H groups showed drug effects, compared to placebo, of reduced motor activity and impulsivity, improved attention (RT), increased HR and HR slowing during RT foreperiods, and decreased ST. Both groups also had decreases in SC responsivity but in different parts of the test. Placebo compared to Day 1 produced increased activity and autonomic arousal but no change in RT. Stimulant drugs thus have similar behavioral and autonomic effects in both N and H boys, but the beneficial effects on behavior do not depend critically on increases in arousal.     

Simultaneous behavioral and neural (cochlear nucleus) measurement during signal detection in the rabbit

Classical conditioning of the rabbit nictitating membrane (NM) response was adapted as a model system for simultaneous measurement of behavioral and neural responses in auditory signal detection. Animals were trained to a 36-dB spectral-level white-noise CS paired with a corneal airpuff US. The CS intensity was then reduced to threshold, using a modified staircase procedure, and responses on detect and nondetect trials were compared for the same stimulus intensities. At threshold, the behavioral NM response was dichotomous, being present on detect trials and completely absent on nondetect trials. In marked contrast, evoked neural unit activity to the CS recorded from the anteroventral cochlear nucleus was clearly present and identical on both detect and nondetect trials, suggesting that the detection “decision” is made more centrally than the cochlear nucleus.     

In defence of iconic memory

According to a model of visual information-processing which originated with Sperling (1960), and which currently enjoys wide acceptance, the contents of brief alphanumeric displays are initially held in a high-capacity fast-decay visual-information store (“iconic memory”). Some of these items are subsequently transferred to a more durable form of storage; the remaining non-transferred items are lost. Observers can select which items are to be transferred on the basis of physical characteristics of the items (such as colour, location, size, shape or brightness).

This model has recently been attacked by Holding (1970, 1971, 1972, 1973), sometimes by claiming that iconic memory does not exist, and at other times by claiming that transfer from iconic memory cannot be selectively controlled by the observer. We argue in this paper that Holding's criticisms are incorrect, and that, even if they were correct, the experiment we report would not be open to objections he has raised concerning previous studies of iconic memory. Despite this, evidence fully supporting the orthodox model was obtained, and we therefore conclude that this model remains tenable.     

Differences Between Adolescents Who Seek Counseling and Those Who Do Not

It was hypothesized that students who seek counseling for occupational and educational planning would differ from those who do not seek counseling in terms of socioeconomic background, certain personality variables, vocational development, and relations with parents. A battery of tests and a questionnaire were given to 245 male students from McDowell County, West Virginia. Of this group, 93 had received counseling (designated as group C) and 152 had not received counseling (designated as group NC). Group C showed a higher socioeconomic background, more n Achievement, and more certainty in vocational planning. The two groups did not differ significantly in occupational aspiration, perception of occupational prestige, self-esteem, fear of failure, relations with parents, and certainty in educational planning.     

Classical conditioning of aggressive display in Siamese fighting fish

Unconditioned aggressive-display behavior elicited by the mirror image of a male Siamese Fighting Fish was brought under the control of a previously ineffective stimulus by classical conditioning. A stimulus light repeatedly paired with mirror presentation came to elicit the complex aggressive-behavior sequence. Relative rates of acquisition of four components of the display were compared. Fin erection and undulating movements were acquired most rapidly while gill-cover erection and frontal approach were acquired most slowly. A discriminative conditioning procedure revealed that the response was specifically elicited by the conditioned stimulus, and not a sensitization artifact.