Extraneous Stimuli Research Articles

Attenuation of ethanol tolerance by a novel stimulus.

A Pavlovian conditioning model of tolerance emphasizes that an association between predrug cues and the systemic effects of the drug contributes to tolerance. On the basis of this model, established tolerance should be attenuated by "external inhibition," i.e., by presentation of a novel, extraneous stimulus. This prediction was evaluated in the present experiment. Rats that were so tolerant to the hypothermic effect of ethanol that they evidenced no drug-induced decrease in temperature were presented with a bright strobe light following ethanol administration. The light precipitated a large decrease in temperature in these rats. These results provide further evidence that tolerance to the hypothermic effect of ethanol is, in part, mediated by learning.

Recognition memory and attentional selection: serial scanning is not enough.

In two experiments, using memory sets of up to 10 letters, the response competition paradigm was employed to investigate the extent to which extraneous visual stimuli interfere with or affect the process of memory search. It was assumed that if selective attention could exclude the effect of noise letters from a Sternberg-type memory comparison process, then there would be an increase in intercept for the reaction time-set size functions but no increase in slope. This result was obtained. However, a large difference in response times to both positive and negative set targets was found when the accompanying noise letters indicated a competing response, as opposed to when they indicated the same response as the target. This implies rapid identification of the nature of both target and noise, independent of a serial comparison process. A modification of a dual process model (Juola, Fischler, Wood, & Atkinson, 1971) in which stimuli activate a familiarity value independent of memory search was suggested to account for these results.

Neuron activity in the motor cortex of a cat with inhibition of a conditioned postural change reflex

A study was made of the neuron spike reactions in the primary motor cortex of the cat in the projection zone of the contralateral forelimb with external and internal inhibition of the conditioned reflex for posture change that consisted of shifting the body weight to the forelimb being studied. Spike responses of the neurons to extraneous stimuli and the conditioned signal were determined to a significant degree by the condition of the animal and its habituation to the signal used. In trained animals, the duration of responses to extraneous stimulation was shorter than in the nontrained. With external and internal inhibition, we observed simultaneous disappearance of conditioned reflex movements and the trace spike discharges connected with them. Frequently extraneous stimulations could suppress trace discharges even when learned movement was present. Extraneous stimulations of a different modality inhibited the reflex to different degrees. The change in neuron spike reaction connected with a conditioned reflex change in posture was similar to well-learned local reflex phenomena.

Freerunning and entrained circadian rhythms in activity, eating and drinking in the cat

Abstract Because cats with pontile lesions exhibit an abnormal behavior that is under photoperiodic control, and because circadian rhythms are implicated in photoperiodic control mechanisms, an effort was made to detect circadian rhythms in the cat. Cats were isolated from all extraneous stimuli in soundproof chambers for extended periods of time. Photocells were used to monitor activity, eating and drinking in different LD cycles, in constant light at two intensities, and in constant dark. Freerunning circadian rhythms were found in the constant conditions, and entrained nocturnal patterns occurred in most of the LD cycles. The higher intensities of ambient illumination disrupted the freerunning rhythms. The freerunning rhythms were always greater than 24 h, ranging from 24.2 to 25 h. Measurements of food intake of cats living in a large colony room, obtained by weighing the food, revealed that a nocturnal pattern of entrainment was not present in the majority of the cats. Instead, most cats in the colon...

Auditory vigilance during hypnosis: a brief communication.

Abstract Attention during hypnosis was measured by means of auditory vigilance tasks which Ss performed while being administered the Stanford Hypnotic Susceptibility Scale, Form C (Weitzenhoffer & Hilgard, 1962). Hypnotic responsivity was significantly and negatively correlated with Ss' performance of the tasks, indicating that relatively responsive Ss detected fewer extraneous environmental stimuli in the form of vigilance task signals than did the less responsive Ss. Discussion ensued as to how this apparent reduction in attention to environmental stimuli came about.

Conditioned approach and withdrawal behavior in pigeons: Effects of a novel extraneous stimulus during acquisition and extinction

Three experiments examined the effects of complete removal of reinforcement and of the introduction of a novel stimulus on conditioned approach and withdrawal behavior exhibited by pigeons in an autoshaping paradigm. Experiment 1 indicated that complete omission of food from the experimental situation resulted in the gradual disappearance of both approach and withdrawal behavior in subjects that had received either explicitly paired or explicitly unpaired conditioning. Subsequent presentation of a novel visual stimulus reinstated both approach and withdrawal. Experiment 2 replicated these findings in a within-subjects, discriminative paradigm. In Experiment 3, presenting the novel visual stimulus during acquisition when approach and withdrawal behaviors were asymptotic did not produce significant disruption of performance. These data suggest that removal of reinforcement leads to the disappearance of withdrawal as well as approach performance, and that subsequent presentation of a novel stimulys reinstates whatever behavior was dominant prior to extinction—a finding that seems analogous to results of experiments concerning proactive interference.

Habituation of the Hoffmann reflex

The human monosynaptic H-reflex system was examined for the presence of several parametric features of habituation. Dishabituation was present, but there was no indication of an increasing rate or extent of habituation during repeated sessions, nor was there any apparent habituation of the dishabituating effect of an extraneous stimulus. Furthermore, there was only a very small effect of stochastic stimulation. There was, however, a substantial effect of voluntary activation: contraction of the soleus tended to prevent habituation, while stretch of the soleus produced sensitization during repetitive stimulation. We conclude that the H-reflex is an extremely simple response system with little or no long-term plasticity.

Developmental trends in distractibility: Is absolute or proportional decrement the appropriate measure of interference?

Since baseline performance varies with age, diminished interference effects found with increasing age do not provide evidence for a developmental trend in distractibility unless their relationship to baseline performance is known. In the present study, baseline difficulty was varied in two speeded classification experiments to investigate whether interference effects due to irrelevant information could best be characterized by absolute or proportional decrement models. In Experiment 1, first graders, third graders, and adults sorted cards on the basis of square size, both in the presence and absence of extraneous stimulus information. In Experiment 2, first graders and adults sorted cards on the basis of the density of a regular array of dots and two kinds of irrelevant information were used. Robust interference effects were found which declined with age. Manipulating discriminability of the relevant stimulus dimension resulted in large changes in sorting time, but interference effects did not vary with baseline difficulty. These results were interpreted as strongly supporting both an absolute decrement model and a developmental trend in distractibility.

Effects of Illustrations on Reading Performance: Implications for Further LD Research

This article reviews available research findings on the influence of illustrations on the reading performance (i.e., word recognition and reading comprehension) of beginning readers in general and in specific subgroups of beginning readers (e.g., poor achievers, low-ability students). Findings suggest that the presence of illustrations interferes with poorly achieving and low-ability children's performance on word recognition tasks and that illustrations are of questionable value to such children's performance on reading comprehension tasks. The possibility that illustrations serve to distract the poor reader's attention from the printed word is discussed. The inability to filter out extraneous stimuli and focus selectively on a task frequently seen in learning disabled children is presented in terms of selective attention theory. Suggestions are offered for further research on the effect of illustrations on learning disabled youngsters' reading performance.

Oxygen consumption in the lizard genus Lacerta in relation to diel variation, maximum activity and body weight.

1. Diel recordings of VO2 under a 12 h Light/12 h Dark regime, constant light or constant dark reveal a strong endogenous diurnal rhythm in L. sicula. L. vivipara show an exogeneous rhythm with activity occurring only in the light whilst L. viridis have a weak endogeneous rhythm that is modified by behavioural factors and inhibited by dark. 2. Standard (or basal) VO2 can only be attained after several hours in an 'indifferent' environment, shielded from extraneous stimuli. Measurements must be at night (light or dark) for unrestrained L. sicula and in the dark (day or night, restrained or unrestrained) for L. vivipara and L. viridis. Intrageneric std VO2 (ml h-1 STPD) = 0.328 W0.76 or 0.216 W0.77 for 1- or 3-days starvation at 30 degrees C for 0.2 to 34 g Lacerta. 3. Intrageneric maximum VO2 (determined for 30 to 60 s of provoked activity during the day) = 2.66 W0.747 at 30 degrees C for 1-days starvation. 4. Respiratory exchange ratio, R = 0.75 or 0.85 for std VO2 after 1 or 3 days starvation and 0.95 and 1.45 for mean daily and max VO2. High R values are considered a result of anaerobic metabolism and hyperventilation during activity.

Speculating about cognitive experiments using schizophrenics.

Several models of selective attention are reviewed, emphasizing how breakdowns in various parts of each model could result in certain attentional deficits. It is concluded that some evidence suggests that the ability to mobilize attention may not be as impaired in schizophrenia as is the ability to choose which stimuli are appropriate for attention. If so, then in any cognitive experiment involving schizophrenics, any schizophrenic subject would be particularly distracted by certain extraneous stimuli, while other schizophrenic subjects would be particularly distracted by other stimuli. The importance of this possibility for cognitive research in schizophrenia is discussed.

Neuroelectric aspects of information-processing by the brain

Auditory, visual, and tactile evoked responses were recorded in a series of experiments in which selective attention and information-processing demands were varied. The technique of “shadowing” was employed, requiring subjects to reproduce, with minimized phase-lag, either auditory or tactile messages. The accuracy and the lag-time of the subject's “shadowing” responses serve as measures both of attentiveness and of the processing demands of the task. This paradigm allows direct assessments of single-channel vs multiple-channel hypotheses of human information-processing. It further permits experimental control of the subject's attention to an extent generally lacking in studies of the relationship between brain responses and attention. The present findings indicate that those current models of human information-processing which impose rigid constraints on the system must be qualified; that both single-channel and multiple-channel features can be disclosed in brain-response data; that systematic relationships obtain between, on the one hand, the information-processing demands of a task and, on the other, the amplitude and variance of cortical responses to otherwise extraneous stimuli presented as the subject performs the task. Theoretical implications of the findings are explored.

Binomial assessment of behavioral-phenotypic variations: constancy of choices, trial effects, and social interaction effects in mass-screened color preferences of quail chicks (Coturnix coturnix japonica).

Individual variations in repeated approach choices between colors by quail chicks were efficiently and reliably identified by methods of binary mass screening and binomial assessment. Choices between a pair of identical white stimuli showed only random variations, which indicated that position habit, systematic alternation, and extraneous stimulus factors did not influence performances. Choices between blue and red colors showed significant individual variations, which were free of influences from changes in the probabilities of choices on repeated trials, interdependence between trials, and interdependence between individual performances of mass-screened subjects. Genetic determination of individual variations were shown by strong responses to bidirectional genetic selection of choices between blue and red, which also introduced small social interaction effects in mass-screened performances. Results are discussed in relation to the use of binomial distribution for identifying phenotypic units and variations in choice behaviors.

Disinhibition and external inhibition of response following septal lesions in rats

Septal-lesioned and sham-operate rats were tested for reactivity to extraneous stimuli (clicks or flashing lights) presented during periods of low or high responding generated by a 120-sec FI schedule of reinforcement. While septal-lesioned rats tended to show greater disinhibition and less external inhibition than sham-operates, the magnitude of the deficits was not considered sufficiently great to warrant the conclusion that the septal syndrome results from increased susceptibility to disinhibition.

Honey Bees: Individual Feeding of Large Numbers of Adult Workers123

A system was devised which is used to individually feed worker honey bees, Apis mellifera L., microdroplets of food at the rate of 300–400 bees/hour. The system reduces extraneous stimuli and utilizes the bees positive phototaxis to lead them to the food. Data on food consumption are reported for bees of different ages fed for varying lengths of time. With an appropriate feeding time, nearly 100% of the worker bees tested consumed the available food.

Effect of Music on Cooperative Problem Solving by Children

One hundred and forty children, 6 to 9 yr. of age, were randomly selected under the auspices of public and parochial school officials in Missoula, Montana. Each of 20 groups was composed of 7 randomly assigned children. Group members traded 8 playing cards with one another in order to obtain a set identical to a display model containing 8 oversized playing cards. The model was visible to Ss at all times. Knowing that completing his or her set would earn 15 MSdrls was an effective incentive in promoting set completion, which each S eventually achieved. Every group individually received only 1 of 4 background sound treatments, with 5 groups ultimately receiving the same treatment. These treatment conditions were: ( a ) art music, characterized by sudden changes in density, volume, timbre, and tempo; ( b ) mood music, in which sonorious variation was at a minimum; ( c ) a recorded, spontaneous reading by 3 adults from different psychology textbooks (n-music control); ( d ) no background sound (no-sound control). All Ss were run under neatly identical conditions of lighting, apparatus arrangement, and extraneous stimuli input. Half the Ss participated after school at a psychology clinic; the other half, at school during the school day. Cooperative behaviors, i.e., S's verbal and physical actions directed toward completing the group task while giving and/or receiving assistance from other Ss, and noncooperative behaviors, i.e., lack of cooperative behavior, were independently assessed by three trained raters. Using time-sampling observation, raters carefully observed S's actions for 5 sec., and for che succeeding 5 sec., checked cooperative and/or noncooperative subcategories into which S's behavior fell, at the time of observation, on prepared rating forms. Using an exact tally matching criterion of subcategory recordings of the rater per observation produced an interrater reliability coefficient of .72, while .87 was obtained for agreement on cooperative and noncooperative assessment per observation. Results were in line with predicted group differences, though not statistically significant ( p z .20). Noncooperative behaviors tended to be greater under conditions of no recorded sound and adults' reading aloud (5-group totals of 39.58 and 35.39 noncooperative responses per minute, respectively), and reduced under art and mood music (5-group totals of 33.71 and 31.38 noncooperative responses per minute, respectively). Also, more noncooperative and fewer cooperative behaviors were noted when playing art than mood music. Participation after school at the clinic and during school hours at school did not influence children's behavior. Suggestions for future studies include revision of the raring form, allowing Ss to choose from alternative reinforcements before beginning the cooperative task, and increasing the task's complexiry to focus on concentration as a function of sound input. Research could investigate music's effect on cooperative responding as a function of S's current level of intellectual functioning, combined social reinforcement and introversion-extroversion tendencies, and gross and fine visual-motor coordination.

Sensitization and dishabituation in the cockroach. Main characteristics and localization of the changes in reactivity

1. 1. Sensitization is described in the cockroach. It is seen as a non-specific increase in the leg motor reflexes following the presentation of a stimulus which elicits an agitation (sensitizing stimulus). 2. 2. This effect is transitory and decreases as the delay between the sensitizing stimulus and the test stimulus is increased. 3. 3. It is shown that the changes in reactivity responsible for Sensitization occur inside the thoracic ganglia, most probably at the level of multimodal interneurons. 4. 4. Dishabituation by an extraneous stimulus may be considered as a special case of sensitization and, as such, is independent of habituation and superimposed on it without disrupting it.

The Effects of Extraneous Mass Mediated Stimuli on Power Relations: Some Preliminary Findings

Five specific directional hypotheses are advanced concerning the effects of extraneous mass mediated stimuli on dyadic power relations as behaviorally defined. The hypotheses generally derive from a simple notion of stimulus confusion and the effects of this confusion both on learning and response probabilities. While only two of the hypotheses show strong statistical significance, all of the hypotheses are directionally correct; an event that would occur only 1/32 of the time under the null hypothesis. The authors conclude that, given their small sample size, the underlying theory may be relatively satisfactory and that it is possible for mass mediated stimuli of an extraneous nature to effect the development of power structures in groups exposed to the media presentations.

The effects of auditory and visual distractors on children's performance in a short-term memory task

Five- and 8-year-old children's performance in a short-term memory task was assessed under two auditory and two visual distraction conditions, as well as with no extraneous stimuli present. Performance under distraction was found to be inferior to that under nondistraction, but the degree of difference was roughly the same at ages 5 and 8, indicating little developmental change in the effects of distraction over this age range. Other findings included differences in the effectiveness of the distractors used and evidence that the children adapted somewhat to the influence of extraneous stimulation.

Dishabituation of the head-shake response in the rat

The effects of presenting a vibratory-auditory extraneous stimulus during habituation of the head-shake response in the rat were studied. In the Within-Trial condition the dishabituatory stimulus was presented during habituation trials, while in the Between-Trial condition it was presented during intertrial intervals. The results revealed that the extraneous stimulus produced a brief period (2–3 sec) of increased responding, followed by a 15- to 20-sec period of response reduction. No evidence for retardation of across-trial habituation was found. The excitatory effect increased across trials and across sessions (i.e., habituation of dishabituation failed to occur). While the results support the interpretation of dishabituation as a temporary, superimposed process of sensitization, they also suggest that dishabituatory phenomena may be more complex than generally thought.