The effect of method of presentation,set, and stimulus dimensions on “same”-“different” reaction times

“Same”-“different” reaction times (RTs) to random shapes varying independently in either brightness, size, or form were studied in an investigation of visual encoding and comparison processes. The comparison process was investigated by having the varying dimension either cued in advance (set) or not cued (no set). The encoding process was investigated by varying stimulus onset asynchronies. No significant difference was found for the set/no-set variables, providing some evidence for an integrality interpretation. However, the serial and parallel models would still hold if the set variable does not affect either dimensional processing rate or order. The significant difference found between the various stimulus onset asynchronies was interpreted as evidence for a limited-capacity encoding mechanism. The results were also consistent with a two-process model of comparison processes.     

Reaction times and error rates for “same”-“different” judgments of multidimensional stimull

Each S indicated whether two successively presented rows of letters were “same” or “different.” Reaction times of the “different” response seemed to indicate that S examined the stimulus letters in a serial, self-terminating manner. However, the reaction times of the “same” response were not consistent with this model. Consequently, it was proposed that S employs simultaneously two distinct processes for comparing stimuli. One process would generate the “different” responses; the other process would generate the “same” responses. Most false “same” responses occurred when the two rows of letters differed minimally. Thus, the false “same” responses appear to result from a failure to detect the difference between the two stimuli. However, when S made a false “same” response, he was aware that he had done so. Therefore, it was suggested that only one of the two comparison processes failed to detect the stimulus difference.     

The effect of explicitly varying the proportion of “same” and “different” responses on sex differences in the Shepard and Metzler mental rotation task

The mental rotation of three-dimensional objects is consistently identified as the most salient cognitive sex difference in humans. The Shepard and Metzler task (1971) requires participants to rotate an object in their “mind's eye” and then compare the shape to a second object to identify if the two objects can be aligned in an identical orientation (warranting a “same” response) or represent mirror image shapes of one another (warranting a “different” response). The mental rotation task not only involves a rotational component but also nonrotational components such as comparison and decision making. Recent research has suggested that the sex difference in mental rotation resides in the nonrotational aspects of “different” decisions specifically. This experiment examined this proposal by varying the proportion of “different” decisions across conditions. Participants were ether exposed to the traditional format (50:50 same/different) or a bias towards (75:25) or away from (25:75) different responses. Contrary to previous research, the sex difference was found to reside in “same” responses that required a greater degree of rotation when assessing error rates in mental rotation. Sex differences in mental rotation error rates were particularly sensitive to the rotational aspect of same responses, not rotational aspects of different responses nor nonrotational aspects of both same and different responses. For reaction time, however, a sex difference emerged in the nonrotational aspects of the task. The bias described here affected these nonrotational aspects of the task, but not the rotational aspects, in line with prediction. A second study reran the experiment without making the bias explicit. Under this implicit bias, no sex differences were identified between conditions.     

Reaction times in a task analogous to “same”-“different” judgment

Subjects responded “yes” if two equal-length strings of letters contained a common letter in a common position; otherwise they responded “no.” Thus, the task was to judge whether all or not all of the letters in one string differed from the letter occupying the corresponding position in the other string. Conversely, in “same”-“different” judgment, the task is to judge whether all or not all of the letters in one string match the corresponding letter in the other string. Thus, common-letter judgment and “same”-“different” judgment are symmetrically related with “no” analogous to “same” and “yes” analogous to “different.” The response “same” is often faster than the response “different.” However, in the common-letter task, “no” was slower than “yes.” More specifically, both the “yes” and “no” reaction times were consistent with a serial self-terminating search. This is precisely what would be expected from Bamber’s (1969) two-process model.     

Decision latencies of “same” and “different” judgments

When a subject is asked to judge whether two stimuli are “same” or“different,” the time he takes to reach the decision same is frequently unequal to the time he takes to reach the decision different. We studied this discrepancy as a function of several variables, including stimulus modality, “codability” vs.“noncodability” of test stimuli, interstimulus interval, and discrimination difficulty. Results of four different experiments performed on a total of 111 subjects showed codability and discrimination difficulty to be the most important factors. Stimuli that are codable (i.e., which can be categorized by absolute judgment) yield a shorter latency for decision same, and noncodable stimuli (i.e., those requiring a reference stimulus for categorization) yield a longer latency for decision same. The modality of test stimuli, the prothetic or metathetic nature of the dimension to be judged, and simultaneous vs. successive presentation of the stimuli appear not to be crucial factors.     

Being a good witness: The roles of benevolence and working memory capacity in rapport’s effect on eyewitness memory

Prior studies suggest that building rapport with eyewitnesses can produce measurable recall improvements, but the underlying mechanisms of rapport’s possible effects on recall remain underexplored. The present study investigated two possible mechanisms for rapport’s impact: (1) improved working memory capacity and (2) increased benevolence. Participants (N = 105) viewed a mock theft video, followed by one of two possible pre-interview interactions: rapport-building or a control interaction. Next, participants completed measures of working memory, altruism, and benevolence (pre-interview and post-interview), before recalling details of the theft. Analyses revealed that, when controlling for the effects of the interaction duration and participants’ pre- and post-interview benevolence, rapport did not affect eyewitness recall directly. However, rapport building did increase benevolence measured after and associated with the substantive eyewitness interview, which in turn predicted more accurate and new details reported, and fewer subjective/other details reported. These findings support benevolence toward the interviewer as a mechanism behind rapport’s effect on eyewitness recall. Implications for investigative interviews in relation to benevolence and motivating reciprocation are discussed.     

Infants’ sensitivity to familiar size: The effect of memory on spatial perception

Two experiments investigated infants’ sensitivity to familiar size as information for the distances of objects with which they had had only brief experience. Each experiment had two phases: a familiarization phase and a test phase. During the familiarization phase, the infant played with a pair of different-sized objects for 10 min. During the test phase, a pair of objects, identical to those seen in the familiarization phase but now equal in size, were presented to the infant at a fixed distance under monocular or binocular viewing conditions. In the test phase of Experiment 1, 7-month-old infants viewing the objects monocularly showed a significant preference to reach for the object that resembled the smaller object in the familiarization phase. Seven-month-old infants in the binocular viewing condition reached equally to the two test phase objects. These results indicate that, in the monocular condition, the 7-month-olds used knowledge about the objects’ sizes, acquired during the familiarization phase, to perceive distance from the test objects’ visual angles, and that they reached preferentially for the apparently nearer object. The lack of a reaching preference in the binocular condition rules out interpretations of the results not based on the objects’ perceived distances. The results, therefore, indicate that 7-month-old infants can use memory to mediate spatial perception. The implications of this finding for the debate between direct and indirect theories of visual perception are discussed. In the test phase of Experiment 2,5-month-old infants viewing the objects monocularly showed no reaching preference. These infants, therefore, showed no evidence of sensitivity to familiar size as distance information.     

Same same but different!? The differential influence of smilies and emoticons on person perception

Emoticons (ASCII-based character strings) and smilies (pictograms) are widely used in computer-mediated communication as substitutes to compensate for the absence of nonverbal cues. Although their usage has been investigated in numerous studies, it remains open whether they provoke differential effects and whether they lead to person perception patterns similar to what is known from face-to-face interactions. Based on findings from research about person perception and nonverbal communication, we investigated the differential effects of smilies and emoticons with regard to recipients' mood, message evaluation, and person perception in an experimental online study (n=127) with a 2(smiley/emoticon) by 2(positive/negative) between-subjects design (with an additional control condition). Results generally support earlier findings, indicating that the valence of the cue (smiley or emoticon) affects the corresponding impression formation. Further, findings concerning the differential influence of both forms of cues show that there are no differences with regard to message interpretation, whereas smiling smilies have a stronger impact on personal mood than smiling emoticons. The perception of a writer's commitment was only altered by smilies, suggesting that they elicit a stronger impact than emoticons.     

The impact of path crossing on visuo-spatial serial memory: Encoding or rehearsal effect?

The determinants of visuo-spatial serial memory have been the object of little research, despite early evidence that not all sequences are equally remembered. Recently, empirical evidence was reported indicating that the complexity of the path formed by the to-be-remembered locations impacted on recall performance, defined for example by the presence of crossings in the path formed by successive locations (Parmentier, Elford, & Maybery, 2005). In this study, we examined whether this effect reflects rehearsal or encoding processes. We examined the effect of a retention interval and spatial interference on the ordered recall of spatial sequences with and without path crossings. Path crossings decreased recall performance, as did a retention interval. In line with the encoding hypothesis, but in contrast with the rehearsal hypothesis, the effect of crossing was not affected by the retention interval nor by tapping. The possible nature of the impact of path crossing on encoding mechanisms is discussed.     

The impact of path crossing on visuo-spatial serial memory: encoding or rehearsal effect?

The determinants of visuo-spatial serial memory have been the object of little research, despite early evidence that not all sequences are equally remembered. Recently, empirical evidence was reported indicating that the complexity of the path formed by the to-be-remembered locations impacted on recall performance, defined for example by the presence of crossings in the path formed by successive locations (Parmentier, Elford, & Maybery, 2005). In this study, we examined whether this effect reflects rehearsal or encoding processes. We examined the effect of a retention interval and spatial interference on the ordered recall of spatial sequences with and without path crossings. Path crossings decreased recall performance, as did a retention interval. In line with the encoding hypothesis, but in contrast with the rehearsal hypothesis, the effect of crossing was not affected by the retention interval nor by tapping. The possible nature of the impact of path crossing on encoding mechanisms is discussed.     

Hand-eye coordination: The role of “motor memory”

Ten Ss attempted to track a visual target, which was moved either by hand (test run) or by a tape recording of the same hand movements (control run). On some test runs, movement of the target lagged behind that of the hand by a fixed amount (.18, .36, .72, or 1.44 sec). The number of saccades occurring on a given test run was divided by the number on the matched control run, and the test/control ratio was studied as a function of the hand-to-target lag time. With lag times of .36 sec or less, the test/control ratios were less than 1. indicating that manual control of the target had a significant effect on oculomotor performance. This effect disappeared at a lag close to .72 sec. The results are discussed in terms of a hypothetical “motor memory.”     

“Of course I will ...”: The combined effect of certainty and level of expectancies on persistence and performance

The importance of performance expectancies for the prediction of regulation of behavior and actual performance has long been established. Building on theories from the field of social cognition, we suggest that the level of performance expectancies, as well as the certainty of the expectancy, have a joint influence on an individual’s beliefs and behavior. In two studies (one cross sectional using a sample of secondary school students and one longitudinal using a sample of university students) we found that expectancies more strongly predicted persistence, and subsequent performance, the more certain the expectancy was. This pattern was found even if prior performance was controlled, as in Study 2. The data give an indication that it may be useful to include certainty as an additional variable in expectancy models.     

Facilitation of both “same” and “different” judgments of letter strings by familiarity of letter sequence

Three experiments employing simultaneous matching were performed to extend recent findings that three kinds of familiarity—familiarity of letter sequences, familiarity of display configuration, and familiarity of letter orientation—facilitate the matching of letter strings for “same” responses and sometimes for “different” responses. It was found that letter sequence familiarity facilitated “same” responses even when the letter strings were in an unfamiliar orientation or configuration and also facilitated “different” responses whenever the task required that a substantial portion of the display be processed before a response could be initiated. A three-stage model of the simultaneous letter-string matching task was developed. This model, which assumes that the same processes account for both “same” and “different” responses, was consistent with findings obtained when there were small differences between string pairs. Discrepant findings obtained when there were large differences between string pairs may have been produced by the premature initiation of responses.     

The effect of presemantic acoustic adaptation on semantic “satiation”

A decrement in the strength of the meaning of a word after rapid repetition of that word has been called “semantic satiation.” This study asked whether this “satiation” might be produced by presemantic acoustic adaptation. Category words were utilized to prime the meaning of target words. The adaptation or “satiation” procedure, 30 rapid repetitions of the primes, was compared with a control condition of 3 repetitions. Participants listened to a series of prime words, each repeated by either the same speaker or many speakers, and then made semantic decisions on target words. When all the repetitions of a prime word are produced by the same speaker, presemantic and semantic repetitions are confounded. When the repetitions are produced by different speakers, presemantic acoustic repetition is abolished. A semantic decrement was detected with single-speaker, but not with multiple-speaker, repetitions of prime words. This study concluded that the semantic “satiation” observed here was a decrement in the activation level of semantic representations induced by presemantic acoustic adaptation.     

The effect of identical word pairs on people's metamemory judgments: What are the contributions of processing fluency and beliefs about memory?

Judgments of learning (JOLs) are higher for identical pairs (dog–dog) than for related pairs (dog–cat). This identical effect may be mediated (a) by processing fluency (i.e., identical pairs are processed faster than related pairs) or (b) by a belief that identical pairs are better remembered or (c) by both factors. In the present work, we assessed the contribution of both factors. We evaluated whether a measure of processing fluency (i.e., self-paced study) mediated the relationship between pair type and JOLs (Experiment 1) and attempted to disrupt processing fluency using an AlTeRnAtInG presentation format (Experiment 2). We also evaluated whether judgments made in the absence of processing fluency demonstrated the identical effect (Experiment 3), and, finally, we had participants read a vignette about an experiment that included both pair types and estimate which pairs would be best remembered (Experiment 4). Evidence from all experiments converged on the conclusion that people's beliefs about how variables affect memory—and not differential fluency—best explain the identical effect, although we cannot entirely rule out the possibility that fluency plays a small role. The outcomes were consistent with the analytic-processing theory of JOLs—namely, when instructed to make JOLs, people adopt an analytic problem-solving approach that involves identifying variation across pairs that plausibly relate to memory and then use this variation to make JOLs.     

The effects of ageing and divided attention on the self-reference effect in emotional memory: Spontaneous or effortful mnemonic benefits?

The self-reference effect (SRE) is a powerful memory advantage associated with encoding in reference to the self (e.g., Rogers, Kuiper, & Kirker, 1977). To explore whether this mnemonic benefit occurs spontaneously, the current study assessed how ageing and divided attention affect the magnitude of the SRE in emotional memory (i.e., memory for emotional stimuli). The sample included a young Full Attention group (young-FA), a young Divided Attention group (young-DA), and an older adult group. The division of attention was manipulated at encoding where participants incidentally studied positive, negative, and neutral trait adjectives in either a self-reference (i.e., rating how well each word describes themselves) or an other-reference condition (i.e., rating how well each word describes another person). Memory for these words was assessed with both recall and recognition tasks. The results from both tasks demonstrated equivalent SRE for all three groups across emotional valence categories of stimuli, suggesting that the SRE is a spontaneous, effortless, and robust effect in memory.     

Recognition memory and awareness: A large effect of study-test modalities on “know” responses following a highly perceptual orienting task

Abstract

Two experiments investigated the effects of varying the correspondence between presentation and test modes on states of conscious awareness in recognition memory. Experiment 1 used visual test items and showed that auditory and visual study modes differentially affected recollective experience and feelings of familiarity assessed by “remember” and “know” responses accompanying recognition: “know” responses were slightly enhanced following visual presentation, but this was largely offset by a similarly small increase in “remember” responses. Experiment 2 employed conditions designed to maximise any effect on “know” responses of the correspondence between presentation and test modes by using a highly perceptual orienting task at study. Under these conditions, there was a large mode correspondence effect on “know” responses. The results support the idea that “know” responses are particularly sensitive to perceptual factors.     

The hippocampal contribution to “Learning and memory”: Information retrieval and comparison

The effects of limbic system after-discharges and ablation upon learning were investigated in 113 adult cats. Learning tasks consisted of active and passive avoidance and pattern and size discrimination. Limbic system after-discharges interfered with performance in learned-avoidance and size-discrimination paradigms. Discharges implicating the ventral hippocampus were the most effective in producing performance decrements; dorsal hippocampal discharges were least effective. The greater the involvement of brain-stem structures by propagated activity, the greater the decrement. There was no motor impairment. Size-discrimination response is impaired to a greater degree than shockavoidance response during limbic discharges. The degree of impairment is in part a function of the type of sensory stimulus and response contingency used. Hippocampal ablation resulted in impairment (response latency changes) in both active and passive avoidance tasks. Acquisition was not impaired. Hippocampal ablation facilitated the development of a stronger position habit in the pattern-discrimination task. Learning deficits which occurred were attributed to impairment of retrieval and comparator mechanisms of neural function. Results support the argument that defective retrieval and/or comparator mechanisms may account for the impaired learning of a diversity of tasks, from simple to complex.     

“P300” and memory: Individual differences in the von Restorff effect

Event-related brain potentials (ERPs) were elicited by words in a free recall paradigm that included a novel item. The P300 component of the ERP is elicited by novel, task-relevant events, and we tested the hypothesis that P300 is a manifestation of the cognitive processing invoked during “context updating.” If the degree to which current representations in working memory need revision is related to P300 amplitude, then the P300 elicited by a given item should be related to the ability to recall that item on a subsequent test. Forty lists were presented to 12 subjects in each of two sessions. The lists were 15 words long, and 1 word, in position 6 through 10, was “isolated” by changing its size. Most subjects recalled these isolated words more often than other words in the same positions (von Restorff effect), and these words also elicited larger P300s than other words. Analysis of variance on the component scores from a principal components analysis revealed that words recalled had a larger amplitude P300 (on initial presentation) than words not recalled. Striking individual differences emerged, and there were strong relationships between the von Restorff effect, overall recall performance, mnemonic strategies, and the association between components of the ERP and recall performance. The overall recall performance of subjects who reported simple (rote) mnemonic strategies was low, but they showed a high von Restorff effect. For these subjects the amplitude of the P300 elicited by words during initial presentation predicted later recall. In contrast, subjects who reported complex mnemonic strategies remembered a high percentage of words and did not show a von Restorff effect. For these subjects P300 did not predict later recall, although a later “slow wave” component of the ERP did. The initial response to isolated items was the same for all subjects (a large P300), and all subjects recognized the isolates faster than other words in a recognition test given at the end of each session. The subjects in whom P300 did not predict recall reported mnemonic strategies that involved organizing the material. These strategies continue long after the time period reflected by P300 (600 msec). Because they were so effective they may have overshadowed the relationship between P300 and recall, which is based on the initial encoding of an event. Our interpretations were further confirmed and clarified from data obtained in a final grand recall and in the recognition test.