The heart rate component of the social reflex in dogs: The conditional effects of petting and person

Five dogs were given a 480-cps tone followed by shock for more than 200 trials. A 200-cps tone was then introduced followed by a person petting the dog at the end of the conditional signal (CS) for 50 trials. Finally, the 480-cps tone-shock (T-S) sequence was reintroduced for five trials, after which the person entered the experimental room and stood beside the dog during one additional T-S sequence. It was observed that both the heart rate (HR) increase to shock, and the HR decrease to petting could be conditioned rapidly (1–5 trials). These findings are discussed in terms of the theory of stimulus substitution in classical HR conditioning. After the person had been made part of a CS for petting, and the T-S sequence reintroduced, the HR increase during the CS was reduced. The HR response to the shock, however, was greater than the response to this US when the dog was alone. A control group, given the same T-S sequence with a person present who had not been a CS for petting, did not show any significant HR changes from the usual response given to the T-S sequence. It is emphasized that these findings, in conjunction with earlier reports, indicate that the cardiovascular system may be a valuable index in studying the psychophysiology of socialization processes.     

Distance discrimination and observer strategy in judgments of relative size

Six paid Ss participated in an experiment designed to assess the effects of observer strategy and the detectability of a distance cue on judgments of relative size. Ss viewed stimulus pairs through a 21-in. tunnel at one end of an 8-ft table. The Standard stimulus, 94 in. from S, was individually paired with three larger and two smaller comparison stimuli 96 in. from S. A slit of light on the table 95 in. from S and 90 deg to his line of sight served as distance cue. Increases in distance detection improved accuracy of relative size judgments when the comparison stimulus was larger than the Standard stimulus, but decreased accuracy when the comparison stimulus was smaller. Magnitude of this effect varied directly with Ss’ post-experimental reports of judgmental strategy. These findings confirm the importance of distance discrimination in judgments of actual size and the necessity to control perceiver characteristics in the study of size-distance relationships.     

An adding result in impression formation

Ss were presented with a highly polarized piece of information, followed by a same-signed moderately polarized piece of information, and were asked whether the second piece of information led them to like the person describedmore, less, or just the same. The obtained percentage ofadding responses was 65%; that is, most of the responses indicated that Ss impression of the person described became more polarized following addition of moderately polarized information (p <.001). More adding was obtained for negatively than for positively evaluated adjectives (p <.05).     

The elusive tradeoff: Speed vs accuracy in visual discrimination tasks

Theoretical models for choice reaction time and discrimination under time pressure must account for Ss’ ability to trade accuracy for increased speed. The fast guess model views these tradeoffs as different mixtures of “all-or-none” strategies, while incremental models assume they reflect different degrees of thoroughness in processing the stimulus. Three experiments sought tradeoffs for difficult visual discriminations, using explicit payoffs to control and manipulate pressures for speed and accuracy. Although guessing was pervasive, the simple fast guess model could be rejected; Experiments II and III obtained tradeoffs even when fast guesses were purged from Ss’ data. Tradeoff functions fit by several formulations revealed: (1) slower rates of increase in accuracy for more similar stimuli, and (2) substantial “dead times” (80–100 msec slower than detection times) before discrimination responses could exceed chance accuracy. Errors were sometimes faster and sometimes slower than correct responses (depending on S’s speed-accuracy trade); the latter effect may reflect a ceiling on S’s achievable accuracy. A final discussion examines implications of the results for models of discrimination under time pressure; it suggests modifications in present models, focusing on the random walk model, and describes an alternative “deadline” model.     

Serial learning of nonsense shapes as a function of instructions controlling labeling

In the literature on visual contrast thresholds for sine wave gratings, little attention has been paid to the psychophysical methods used to obtain these spatial-frequency response curves. Here we report a comparison of such data obtained by two quite different psychophysical methods, but otherwise under identical conditions, using five Ss. Both experiments were run by computer: (1) In the method of adjustments, the computer program merely controls the order of the stimuli and records S’s contrast settings. (2) In the forced-choice staircase (FCS) technique, the program determines how often S can discriminate the sinusoidal grating from a uniform field, informs S of his accuracy, controls the stimulus contrast on the basis of S’s preceding responses, and brackets his threshold by a series of successive approximations. Method 2 eliminates criterion effects that occur in Method 1, and hence tends to minimize individual differences. However, the FCS technique requires an order of magnitude more observing time to obtain equally smooth contrast sensitivity curves. FCS also increases the/overall sensitivity of some Ss by as much as five times, but it does not significantly change theshape of the contrast sensitivity curve; both methods show strong effects of lateral inhibition at low spatial frequencies.     

The effects of instructions,fixed rate of presentation,and complexity on free looking time

The effect of stimulus complexity, prior experience with a short or long fixed rate of presentation (FRP) and S’s knowledge concerning the purpose ot the experiment on free looking time (FLT), was examined. Results indicated that under all conditions, Ss view complex stimuli longer than simple. A long FRP produced longer FLT than did a short FRP for Ss uninformed of the purpose of the experiment, hut FRP had no effect on FLT for Ss who were informed.     

Restrictive conditions for the occurrence of psychological reactance: Interpersonal attraction,need for social approval,and a delay factor

The purpose of the present experiment was to show that the occurrence of psychological reactance is diminished when a person a) estimates the freedom eliminating source of social influence as highly attractive, and b) shows strong need for social approval and that c) psychological reactance might be stored up when the actual freedom eliminating social influence is too strong. In an experiment with 3 phases female students served as Ss. Two partners (S and stooge) had to decide whether or not to answer an item from a set of everyday questions with two choice alternatives. In the case of a positive decision they had to give their judgments covertly. In the first phase the S decided whether to answer or not; then the stooge urged the S not to answer a special set of questions. In the second phase the stooge announced her decision whether to answer a question or not and she left out the ‘crucial’ items. In the third phase the S answered the items alone since the stooge left the room for a short time having good reasons. The independent variables were interpersonal attraction: high vs. low (manipulated by instruction) and social desirability: high vs. low (measured by median split-half of the scores of a German version of the Marlowe-Crowne-scale). Reactance was measured as the number of answers to the crucial items in phase 3 in relation to the previous phases. The delay effect of psychological reactance was tested by a comparison of answers in phase 2 and 3. The data lent support to the first (attraction) and third (delay) experimental hypotheses stated.     

Attribution of intention as a function of physiognomy

Ss agree in attributing character traits to strangers’ photographs, but there has been no explication of what such labels imply. Presumably. trait names either mediate or reflect Ss’ expectations of such strangers" likely social behaviors: but that remains undemonstrated, and we may be able to study such physiognomy-tied expectations directly. Sampling problems confront trait studies and intention studies alike, but the present research showed that Ss’ expectations of a person’s behavioral intentions, as measured by alternative interpretations of short “scenarios,” were reliably influenced by that person’s photograph.     

Teacher Versus Peer Models

Female Ss (N=80) observed either a teacher or a peer model (M) demonstrate a motor task with either high or low performance ability. The effects’ of viewing these live performances on S’s subsequent motor performances were examined. After the observation of M, S’s performance in the presence or absence of the observed M was investigated. A Control Group consisting of 20 Ss, viewing no M, was compared to ail other groups for analysis. Results of the M Type × M’s Ability Level × M Presence design indicated that those in the Control Group had significantly lower performances than all other groups on all blocks of trials. In addition, across all trial blocks, S’s performances were enhanced subsequent to having viewed a skillful teacher M. Upon observing M’s demonstration, Ss exhibited increased matching responses and better performances when performing in the presence of M.     

Summation of excitatory and inhibitory control produced by traditional tone-shock contingencies and autocontingencies

Previous research has demonstrated that rats can use unsignaled shock to predict subsequent periods free from shock. This shock-no shock stimulus arrangement, termed an autocontingency, has appeared less likely to exert behavioral control when a traditional tone-shock contingency was simultaneously available. The present research examined the generality of CS-US contingency dominance in a conditioned suppression paradigm by using a summation test in which “probe” stimuli derived from tone-shock contingencies were superimposed upon responding maintained by an autocontingency. In experiment 1, an inhibitory CS accelerated responding only when responding was normally suppressed by the autocontingency. In experiment 2, an excitatory CS failed to yield conditioned suppression during an inhibitory (accelerative) period produced by the autocontingency. Unlike our previous findings (e.g., Davis, Memmott & Hurwitz, 1975), these results do not support a general notion of tone-shock contingency dominance over autocontingencies. Behavioral control by autocontingencies appears robust and “holds its own” in summation with both excitatory and inhibitory CSs derived from traditional contingencies.     

Perceptual modification of sensitivity (d′): Modifying temporal resolution by the consistency of the spatial configuration

The major question in this study was whether perceptual modifications are basic alterations in a sensory system or changes in the S’s criterion. Four Ss were given prolonged training with a particular two-lined stimulus, deciding whether the stimulus had been presented in one continuous presentation or in two successive presentations with a temporal gap. The results confirmed the hypothesis, generated from modifications in visual cells, that the S’s sensitivity (d′) to a two-lined stimulus could be disrupted by the presentation of one original line with a new line. In contrast, two entirely new lines had little effect on the S’s sensitivity. A discussion of the results also indicated that temporal resolution must be a plastic process which depends on the consistency of the spatial configuration as well as temporal parameters.     

An analysis of aftereffects in the measurement of the correction effect

Ss, under prismatic viewing, aligned a spot of light to the apparent straightahead first in the dark and then under illumination. Ss made these judgments either by controlling the spot themselves or by directing E in moving it. For both types of alignment procedures, judgments were significantly more veridical in the illuminated room (correction effect). Aftereffects, measured after both the spot alignment in the dark and in the light, were found to be significant only when S moved the stimulus. These results contradict the argument that the egocentric localization processes involved in the production of the correction effect itself are the basis of the aftereffects obtained.     

SOCIAL DISTANCE NORMS IN CANADA: EFFECTS OF STIMULUS CHARACTERISTICS AND DOGMATISM*

The effects of stimulus person characteristics (viz., race, occupational status, religion, and nationality) and the respondent's level of dogmatism upon the social distance responses of a sample of Canadian university students were examined. Occupational status, race, and nationality of the stimulus person emerged as significant determinants, with occupational status being by far the most important. Dogmatism was also correlated with social distance responses. Highly dogmatic persons, but not those low in dogmatism, focused on occupational status in deciding acceptable bounds of intimacy with others. Several explanations for the prominence of occupational status as a social distance cue are discussed. As well, directions for future research into social distance norms in Canada are suggested.     

Evidence for all-or-none preperceptual processing in perceptual set

“Set” is known to improve the accuracy of report of the stimulus attributes for which Ss are set to respond. The set may produce this effect by acting on either preperceptual or postperceptual processes, or both. To elucidate the manner by which set produces its effect, this paper explores the consequences of two assumptions concerning set (1) On any given trial, a S is either “set” or “not set”: (2) if “set” by the stimulus information. S’s perception of the stimulus actually improves, whereas, if “not set” by the stimulus reformation, the S’s report correctness is improved by an independent interaction of stimulus and set information on a response process. Evidence is provided for both these assumptions. In addition. It is argued that only set given before stimulation can affect a perceptual process.     

The effects of stimulus familiarization on patterns of visual selection

Patterns of visual selection were recorded as Ss viewed pairs of stimulus drawings in which the two members were either both incongruous or both banal. Prior to presenting the paired stimuli, S was preexposed to either one member of the stimulus pair or to the incongruous or banal counterpart of one member of the stimulus pair. The results indicate that: (1) preexposure to a stimulus reduced its potential to elicit looking responses, and the magnitude of that reduction was greater for incongruous stimuli than for banal stimuli; (2) preexposure to an incongruous stimulus affected the potential of its banal counterpart to elicit looking responses, but preexposure to a banal stimulus did not affect the potential of its incongruous counterpart to elicit similar responses; and (3) the reduced potential of the preexposed member of a stimulus pair to elicit looking responses waned after 10 sec. These results were discussed in light of an “information-conflict resolution” model of visual selection.     

Stimulus information and stimulus interference in bisensory short-term memory

An attempt was made to determine if Ss’ strategy of retaining stimulus material changed under conditions of bisensory simultaneous stimulation when one of the two inputs was relevant information as opposed to interference. Thus in Group 1 Ss were stimulated bisensorily, attended to both inputs (information), but recalled only one input. Ss in Group 2 were stimulated bisensorily, attended to only one input, and recalled only that input (interference). It was found that S’s efficiency of recall was decreased in the information condition (Group 1) but strategy was not altered. In both groups, Ss performed similarly; performance was in turn similar to that observed in the typical bisensory situation, i.e., where both channels are recalled.     

Role of response imagery on stimulus recognition*

This experiment investigated the role of response imagery on recognition of stimulus terms following associative training. Ss learned to associate 12 high-imagery or low-imagery responses with trigram stimuli by the study-associative matching procedure. Half the pairs were consistently paired and half were re-paired anew on each trial. Following associative training, Ss were given a stimulus recognition and an associative matching task The results indicated that the probability of stimulus recognition, given correct associative matching, was greater when the responses were high-imagery rather than low-imagery. In contrast, no rehable response imagery effects were found for the probability of stimulus recognition, given incorrect associative matching. It was argued that the locus of the response imagery effect was primarily during retrieval rather than during encoding.     

The effects of coding procedure on human information transmission

Three different coding schemes, i.e., transformations between stimuli and responses, were used in a continuous information transmission situation. The stimuli were groups of binary digits and S was required to transform these into verbal equivalents of combinations formed by taking various sets of the English letters. Three codes, one based on communication theory, one based on Miller’s (1956) chunking hypothesis, and a combination of the first two were used. In addition, two levels of stimulus redundancy, zero and 0.5 were used. Time to complete the task and errors were the de-pendent variables. The Ss were run for twelve days. The basic result was that Ss transmitted information at a constant rate regardless of the code or redundancy level used.     

A note on the parallel processing of single-featured forms

Single-featured forms (vertical and horizontal lines) were presented to Ss both successively and simultaneously, the same form being presented one, two, or four times. Hit rates (HRs)for both simultaneous and successive presentations of two and four forms exceed the single-form HR. The HR for four successively presented forms (1F4) exceeds the four simultaneous form (4F) HR. The HR increases in the simultaneous conditions were not found in a previous study using single-featured forms. The discrepant results of the two studies indicate that energy level of stimulus presentation and confusability among forms affect the magnitude of HR increase in the simultaneous conditions. The finding of a greater 1F4 HR than 4F agreed with previous findings, indicating that with single-featured stimulus forms, Ss do not process simultaneous displays in parallel.     

Reaction time as a function of stimulus uncertainty on a single trial

In a discrete choice-reaction-time experiment, reaction times were measured between the onset of a light and the start of S’s pencil toward that light. The reaction time of unpracticed Ss, not aware that their first “practice” trial was being measured, increased as a linear function of stimulus uncertainty. Since this occurred without any prior experience, the effect must have been due to S’s set or expectancy regarding the nature of the future task, formed while the instructions for the task were being given.