Effects Of Stimulus Complexity Research Articles

The Effects of Stimulus Complexity and Sensory Modality on Reaction Time in Normal and Retarded Readers

Intra- and crossmodal performance of normal and retarded readers was compared in a reaction-time task. Both reading groups showed slower crossmodal than intramodal shifting. This effect occurred equally for both reading groups. Differences between the two groups occurred, however, when a complex visual stimulus was present. The complex stimulus resulted in the retarded readers showing slower reaction times to other stimuli in that setting. This effect occurred for stimuli both within and across modalities. The results suggested that the demands of stimulus complexity within the visual modality rather than the demands of crossmodal shifting were related to reading ability.

The Effects of Stimulus Complexity and Sensory Modality on Reaction Time in Normal and Retarded Readers

The Effects of Stimulus Complexity and Sensory Modality on Reaction Time in Normal and Retarded Readers

Attention and memory cues in concept learning as a function of task complexity and age

The effects of attention and memory cues on concept learning performance were investigated as a function of task complexity and grade level of Ss. It was found that: (1) the attention and memory cues were closely interrelated in their effects upon performance with both significantly improving performance at all but the lowest levels of complexity; (2) both types of cues considerably lessened the effect of stimulus complexity upon performance; and (3) the attention cue elicited the best performance from Ss in the first through ninth grades, while the memory cue elicited the best performance from 4-year-old and kindergarten Ss.

Effects of stimulus complexity on the perception of brief temporal intervals.

Effects of stimulus complexity on the perception of brief temporal intervals.

Exploration, curiosity, and play in young children: Effects of stimulus complexity.

Exploration, curiosity, and play in young children: Effects of stimulus complexity.

The effect of stimulus complexity on retrieval of information frown memory

Eighteen Ss performed an item recognition task involving memorized lists of one, two, and three nonsense forms at one of two levels of stimulus complexity. Analysis of RT-set size functions and serial position functions suggested that (a) when the memorized list consisted of simple figures, Ss engaged in a serial exhaustive search of items stored in memory prior to responding and (b) when the memorized items were complex, an increase in set size was accompanied by a change in search strategy from a backward self-terminating search to a random self-terminating search.

Effects of stimulus complexity and dimensionality on children's discrimination of forms.

In each of 2 experiments, kindergarten children were presented with either simple stimuli (e.g., square, triangle, regular trapezoid) or complex stimuli (irregular pentagons) in a form-discrimination task. Half the Ss in each experiment were trained on 2-dimensional stimuli and half on 3-dimensional stimuli. Simple forms were significantly easier to discriminate than complex forms. Neither stimulus dimensionality nor the interaction between dimensionality and complexity was significant.

The effect of stimulus complexity on human cyclofusional response

Objective measurement of human cyclofusional response was carried out, using a binocular recording technique. Increasing stimulus complexity was found to result in an increased cyclofusional amplitude. The greater cyclofusional amplitude resulting from increased stimulus complexity is realized by an increased central response, while compensatory eye movements, if they indeed occur, play a minor role. Hence the extent of Panum's fusional areas can no longer be considered constant and their dependence upon stimulus parameters should be recognized.

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.

Effects of Stimulus Complexity of the Auditory Evoked Response

Sixty-four subjects were run in an experiment to determine the effect of stimulus complexity on the auditory evoked (Vertex) response. The 760-msec stimulus consisted of 10 bursts of pure tone with 40-msec burst durations and interburst intervals. Stimulus complexity was varied by utilizing tone bursts of different frequencies within the stimulus. Four levels of complexity (1, 2, 5, and 10 frequencies per stimulus) were used. Tone order in the multifrequency conditions was quasirandom, with each frequency represented an equal number of times per stimulus. The frequencies were balanced for loudness. In each condition, 500 stimuli were presented with an interstimulus interval of 1.2 sec. Recording of the responses was by electrodes placed at vertex and mastoid, with a forehead ground. The 500 responses were broken down in a signal averager into 20 averages of 25 responses each. These 20 waveforms were then averaged across subjects within conditions. Results indicate that increasing stimulus complexity produces an exaggerated negative excursion at about 350 msec after stimulus onset. A more rapid habituation of the N1−P2 complex is also present as compared to simpler stimuli.

Effects of stimulus complexity, interstimulus interval, and masking task conditions in differential eyelid conditioning.

Effects of stimulus complexity, interstimulus interval, and masking task conditions in differential eyelid conditioning.

Positive transfer of familiarization training to recognition performance: Effects of stimulus complexity and association value

Effects of complexity and association value of random shapes on the amount of transfer from stimulus familiarization training to a later recognition task were examined. Familiarization training resulted in strong positive transfer effects to later recognition performance. Increases in stimulus complexity were associated with increases in recognition performance only when familiarization training was administered. It was suggested that increases in stimulus complexity provide more usable stimulus information for recognition but that such information is only effectively utilized by S for recognition when familiarization training is provided.

Age differences in the effects of stimulus complexity and symmetrical form on choice reaction and visual search performance

Random shapes differing in complexity (5, 10, 20, or 40 angles) and form (symmetrical, S, or asymmetrical, A) were presented to children and adults in two timed pattern-discrimination tasks. In Experiment I, college students and fourth-graders judged the class membership (complexity) of singly displayed shapes in a choice-reaction task. In Experiment II, another sample of college adults, and third- and sixth-graders were individually given a visual search task in which linear displays of shapes were scanned rapidly for the location of a “target” pattern. Both experiments indicated a positive relationship between performance speed and age and trials, and slower performance with increasing stimulus complexity. However, symmetry exerted opposite effects in the two tasks, a finding which probably reflected the differing demands in Ss' discriminating between-class differences (between classes of complexity in Exp. I) and within-class differences (between members of the same class, in Exp. II). The several interactions among age, stimulus variables, and practice effects provided informative analyses of age differences in discrimination performance. The data suggested that adults respond to bilateral symmetry and asymmetry as distinctly different classes of form, whereas children show less sensitivity to this property of patterns. An interpretation of the consistently superior performance of the older Ss focused upon the age-correlated development of coding rules for dealing with stimulus complexity.

The effects on eye movements of complexity, novelty, and affective tone

The major purpose of this study was to investigate the effects of stimulus complexity, novelty, and affective tone on the direction of eye movements of male college students. Motion pictures were taken of S’s eye while he viewed pairs of stimuli. In no instance, in any part of the 10 sec. viewing interval, did Ss as a group fixate longer on unpleasant stimuli when they were paired with either pleasant or neutral stimuli; and pleasant stimuli consistently dominated neutral stimuli. Also, novel stimuli and complex stimuli tended to dominate their non-novel and less complex competitors. Differences in instructions were found to markedly affect the magnitude but not the direction of fixation-dominance.

Looking time: The effects of stimulus complexity and familiarity

During a 10 min. stimulus familiarization period, three groups of 60 Ss each received either 0, 10, or 20 sec. of familiarization on each of 30 experimental stimuli: 10 each of low, medium, and high stimulus complexity. All Ss then viewed the experimental stimuli in a second task, during which they could look at each stimulus for as long as they wished (free looking). For half the Ss in each group, free looking was administered immediately after the familiarization period. The remaining Ss received free looking 48 hr. later. The results replicated earlier research which has shown that free looking time is inversely related to stimulus familiarity, and directly related to stimulus complexity. Unlike earlier findings, the data suggested that with a 48 hr. delay between familiarization and free looking, a stimulus can, at least partially, recover from the decrement in looking time produced by 10 sec. of familiarization.

Effects of stimulus complexity and restrictive responses.

Effects of stimulus complexity and restrictive responses.

Stimulus uncertainty as a variable in the development of conceptual ability

The principal aims of the investigation were to study (a) the effect of age and stimulus complexity on concept attainment and (b) the role of stimulus cues in the solution of concept attainment problems. Two hundred and seventy Ss, 4-, 6-, and 8-years old, were divided into 27 experimental groups, constituting a factorial design of three ages, three levels of stimulus complexity, and three concepts. The concepts were form, color, and size, presented with 0, 1, or 2 irrelevant stimulus dimensions. Significant age and stimulus complexity effects were obtained for errors and for per cent criterion Ss per group. Measures of information transmission revealed that the responses of criterion Ss were governed primarily by the relevant (reinforced) stimulus dimension under all conditions. The total amount of information transmitted by successful Ss correlated positively with the age of the learner. The responses of noncriterion Ss were determined significantly by irrelevant stimulus cues and position biases. Total information transmission in the failing group was negatively correlated with age. Older failures did not respond consistently to one cue while younger children tended to perseverate on irrelevant stimulus dimensions. Differences in information transmission were interpreted as reflecting limitations in memory or variations in strategy. Perseveration may have resulted from the reinforcement contingencies. Experimental methods of testing the interpretations were proposed.

Effects of stimulus complexity and induced arousal on paired-associate learning

Three experiments on paired-associate learning were carried out, with disyllabic male first names as response terms. Exps. I and II, in which visual patterns served as stimulus terms, showed significantly fewer correct recalls when stimulus terms were more complex or incongruous. Familiarization of half of the stimulus terms before the first training trial made no appreciable difference, which casts doubt on the attribution of the effect to differences in arousal value. The effect seemed more likely to be due to presence or absence of symmetry. White noise was used in Exp. II as a means of manipulating arousal. Recall was impaired when S s were subjected to 72 db white noise during training and testing, and there was some indication that recall might be improved by 58 db white noise. In Exp. III, stimulus terms were single adjectives, homogeneous double pairs of adjectives, and heterogeneous double pairs. One quarter of the items were learned under white noise and tested the next day under white noise, one quarter learned without white noise and tested under white noise, one quarter learned under white noise and tested without white noise, and one quarter learned and tested without white noise. Five groups of S s had different intensities of white noise ranging between 35–75 db. It was found that recall, both on the training day and on the test day, was worse with heterogeneous double than with homogeneous double stimulus terms but equal with homogeneous double and single stimulus terms, corroborating the hypothesis that the symmetry factor had been responsible for the results of Exps. I and II. On the training day, there was significantly less recall with white noise than without white noise. On the test day, items learned under white noise the day before were recalled significantly more often than others, although there was a significant interaction between presence of white noise on training and test days. No significant effect of white noise during the test trial appeared. Variations in white-noise intensity had no significant influence.

Effects of stimulus complexity and incongruity on duration of EEG desynchronization

1. 1. Human subjects were exposed to a sequence of visual patterns, each shown twice consecutively. Exposures lasted 3 sec and were separated by intervals of 15 sec. The patterns belonged to eight categories, representing various complexity and incongruity variables. 2. 2. More complex or incongruous patterns evoked, on the average, longer desynchronization than less complex or incongruous patterns (6.4 sec as compared with 5.8 sec). The difference was found to be statistically significant when the data for all eight categories were examined together and when the data for four of the categories (representing Irregularity of Arrangement, Amount of Material, Incongruity and Random Redistribution) were examined separately. 3. 3. No significant difference appeared between first and second presentations of the same patterns or between subjects who were extrinsically motivated (told to attend carefully for the sake of a later recognition test) and not extrinsically motivated, and none of the interactions was significant. There was, however, a significant tendency for desynchronization to grow shorter as the session continued. 4. 4. The findings are discussed in relation to theoretical and experimental work on motivational aspects of exploratory behavior and related phenomena.

Illusory changes of distinct speech upon repetition--the verbal transformation effect.

If a loop of tape plays a clearly pronounced word or phrase over and over, sudden shifts seem to occur in what is being said. This ‘verbal transformation effect’ continues at frequent intervals during continued stimulation, sometimes introducing a new form, sometimes returning to a form already reported. The illusion was found for all stimuli used: from a word with two speech sounds to complete sentences. Quantitative measures were obtained of the effect of stimulus complexity, loudness, masking noise, and repetition rate. Transitions frequently involved a very great degree of phonetic distortion and often exhibited semantic consistency.