The effect of interstimulus interval on the discrimination of cryptic targets.

In 4 experiments, pigeons were required to discriminate between the presence and absence of cryptic targets. Experiments compared performance when 1 stimulus type appeared in a session (run condition) with performance when 2 types appeared intermixed (mixed condition). When the interstimulus interval (ISI) was short between successive presentations of the same stimulus, within-session improvements occurred in both run and mixed conditions (Experiments 1, 2, and 3). Experiment 4 showed that within-session improvements can occur as a result of mini-runs of 1 stimulus type followed by mini-runs of the other. These results suggest that several independent memory traces may be primed simultaneously and that performance is determined by the extent to which traces of stimuli have decayed by the time of their next presentation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cross-language tests of hemispheric strategies in reading nonwords.

Four experiments explored the effects of specific language characteristics on hemispheric functioning in reading nonwords using a lateralized trigram identification task. Experiment 1 tested whether this is due to the test language or to the native language of the participants. Results showed that native language had a stronger effect on hemispheric strategies than test language. Experiment 2 showed that latency to target letters in the CVCs revealed the same asymmetry as qualitative errors for Hebrew speakers but not for English speakers and that exposure duration of the stimuli affected misses differentially according to letter position. Experiment 3 used number trigrams to equate reading conventions in the 2 languages. Qualitative error scores still revealed opposing asymmetry patterns. Experiments 1-3 used vertical presentations. Exp 4 used horizontal presentation, which eliminated sequential processing in both hemispheres in Hebrew speakers, whereas English speakers still showed sequential processing in both hemispheres. Comparison of the 2 presentations suggests that stimulus arrangement affected qualitative errors in the left visual field but not the RVF for English speakers and in both visual fields for Hebrew speakers.… (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Object substitution masking: When does mask preview work?

When a target is enclosed by a 4-dot mask that persists after the target disappears, target identification is worse than it is when the mask terminates with the target. This masking effect is attributed to object substitution masking (OSM). Previewing the mask, however, attenuates OSM. This study investigated specific conditions under which mask preview was, or was not, effective in attenuating masking. In Experiment 1, the interstimulus interval (ISI) between previewed mask offset and target presentation was manipulated. The basic preview effect was replicated; neither ISI nor preview duration influenced target identification performance. In Experiment 2, mask configurations were manipulated. When the mask configuration at preview matched that at target presentation, the preview effect was replicated. New evidence of ineffective mask preview was found: When the two configurations did not match, performance declined. Yet, when the ISI between previewed mask offset and target presentation was removed such that the mask underwent apparent motion, preview was effective despite the configuration mismatch. An interpretation based on object representations provides an excellent account of these data. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual priming of inverted and rotated objects.

[Correction Notice: An erratum for this article was reported in Vol 36(4) of Journal of Experimental Psychology: Learning, Memory, and Cognition (see record 2010-12650-021). In the article, there was an error in the sixth sentence of the abstract. The sentence should read “Experiments 2 and 3 demonstrated that although identification was sensitive to orientation, visual priming was relatively invariant with image inversion (i.e., an image visually primed its inverted counterpart approximately as much as it primed itself).”] Object images are identified more efficiently after prior exposure. Here, the authors investigated shape representations supporting object priming. The dependent measure in all experiments was the minimum exposure duration required to correctly identify an object image in a rapid serial visual presentation stream. Priming was defined as the change in minimum exposure duration for identification as a function of prior exposure to an object. Experiment 1 demonstrated that this dependent measure yielded an estimate of predominantly visual priming (i.e., free of name and concept priming). Experiments 2 and 3 demonstrated that although priming was sensitive to orientation, visual priming was relatively invariant with image inversion (i.e., an image visually primed its inverted counterpart approximately as much as it primed itself). Experiment 4 demonstrated a similar dissociation with images rotated 90° off the upright. In all experiments, the difference in the magnitude of priming for identical or rotated–inverted priming conditions was marginal or nonexistent. These results suggest that visual representations that support priming can be relatively insensitive to picture-plane manipulations, although these manipulations have a substantial effect on object identification. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attention, exposure duration, and gaze shifting in naming performance.

Two experiments are reported in which the role of attribute exposure duration in naming performance was examined by tracking eye movements. Participants were presented with color-word Stroop stimuli and left- or right-pointing arrows on different sides of a computer screen. They named the color attribute and shifted their gaze to the arrow to manually indicate its direction. The color attribute (Experiment 1) or the complete color-word stimulus (Experiment 2) was removed from the screen 100 ms after stimulus onset. Compared with presentation until trial offset, removing the color attribute diminished Stroop interference, as well as facilitation effects in color naming latencies, whereas removing the complete stimulus diminished interference only. Attribute and stimulus removal reduced the latency of gaze shifting, which suggests decreased rather than increased attentional demand. These results provide evidence that limiting exposure duration contributes to attribute naming performance by diminishing the extent to which irrelevant attributes are processed, which reduces attentional demand. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

"Visual priming of inverted and rotated objects": Correction to Knowlton et al. (2009).

Reports an error in "Visual priming of inverted and rotated objects" by Barbara J. Knowlton, Sean P. McAuliffe, Chase J. Coelho and John E. Hummel (Journal of Experimental Psychology: Learning, Memory, and Cognition, 2009[Jul], Vol 35[4], 837-848). In the article, there was an error in the sixth sentence of the abstract. The sentence should read “Experiments 2 and 3 demonstrated that although identification was sensitive to orientation, visual priming was relatively invariant with image inversion (i.e., an image visually primed its inverted counterpart approximately as much as it primed itself).” (The following abstract of the original article appeared in record 2009-09620-008.) Object images are identified more efficiently after prior exposure. Here, the authors investigated shape representations supporting object priming. The dependent measure in all experiments was the minimum exposure duration required to correctly identify an object image in a rapid serial visual presentation stream. Priming was defined as the change in minimum exposure duration for identification as a function of prior exposure to an object. Experiment 1 demonstrated that this dependent measure yielded an estimate of predominantly visual priming (i.e., free of name and concept priming). Experiments 2 and 3 demonstrated that although priming was sensitive to orientation, visual priming was relatively invariant with image inversion (i.e., an image visually primed its inverted counterpart approximately as much as it primed itself). Experiment 4 demonstrated a similar dissociation with images rotated 90° off the upright. In all experiments, the difference in the magnitude of priming for identical or rotated–inverted priming conditions was marginal or nonexistent. These results suggest that visual representations that support priming can be relatively insensitive to picture-plane manipulations, although these manipulations have a substantial effect on object identification. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Summation and configuration: Stimulus compounding and negative patterning in the rabbit.

The present experiments were aimed at identifying the interactions among atomistic and configural processes in governing response acquisition to a compound stimulus and its components. To that end, the acquisition of the rabbit's nictitating membrane response was examined in (a) "stimulus compounding," which entailed reinforced training with two separate stimuli—namely a tone and a light—plus tests with a compound of the two stimuli, and (b) "negative patterning," in which reinforced presentations of the separate stimuli were interspersed with a large number of unreinforced compound presentations. In Experiments 1 and 2, stimulus compounding produced summation effects—that is, a higher level of responding to the compound than to either component stimulus. In the negative patterning schedule, responding to the unreinforced compound declined as a direct function of the stimulus duration, which was varied across values of 300, 800, 1,300, and 1,800 ms in a delay conditioning paradigm. Experiment 3 demonstrated that a negative patterning outcome emerged only when the duration of both the components and the compound was relatively long, for example, 1,800 ms. Together the results support a "unique stimulus hypothesis," which contends that responding to a compound is jointly governed by coexisting representations of a compound and its components. Furthermore, the compound representation appears to require more time to recruit than do those of the components. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Overshadowing and stimulus duration.

In 3 experiments, the authors investigated the effect of stimulus duration on overshadowing. Experiments 1 and 2 examined responding to a target conditioned stimulus (CS1) when it was conditioned in compound with a coterminating overshadowing stimulus (CS2) that was longer, shorter, or of the same duration (the long, short, and matched groups, respectively). Equal overshadowing of conditioning to CS1 was obtained in all 3 conditions relative to a control group conditioned to the light alone. There were, however, differences in responding to CS2 as a function of its absolute duration. Experiment 3 examined the contribution of the food-food interval/CS onset-food interval ratio to these findings. In Experiments 1 and 2, the ratio differed for the overshadowing CS but not for the target CS. In Experiment 3, this arrangement was reversed, but the pattern of results remained the same. The implications of these findings for trial-based and real-time models of conditioning are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Habituation of the EEG arousal response in rats: Short- and long-term effects, frequency specificity, and wake–sleep transfer.

In 3 experiments with 78 male Holtzman albino rats, presentation of auditory stimuli over interstimulus intervals (ISIs) of several minutes to sleeping Ss produced significant habituation of the EEG arousal response. The arousal response habituated to an asymptote after only 2 or 3 stimulus presentations. Little or no spontaneous recovery occurred between sessions separated by 24 or 72 hrs. The habituation produced by a single stimulus presentation was retained for at least 24 hrs, and orderly habituation was shown with a 24-hr ISI. Approximately 90% retention of habituation was shown 32 days following 10 stimulus presentations, and some degree of retention was shown for as long as 50 days. After habituation had reached a long-term asymptote, 600 stimulus presentations over 2-sec ISIs produced further response decrements, but these decrements recovered completely within a matter of minutes and responsiveness returned to the previously established long-term asymptote. Habituation was shown to be frequency-specific over both 24-hr and 32-day intervals. Habituation produced by stimulus presentations to awake Ss transferred to the condition in which stimuli were presented to sleeping Ss. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sources of sentence constraint on lexical ambiguity resolution

Results from a series of naming experiments demonstrated that major lexical categories of simple sentences can provide sources of constraint on the interpretation of ambiguous words (homonyms). Manipulation of verb (Experiment 1) or subject noun (Experiment 2) specificity produced contexts that were empirically rated as being strongly biased or ambiguous. Priming was demonstrated for target words related to both senses of a homonym following ambiguous sentences, but only contextually appropriate target words were primed following strongly biased dominant or subordinate sentences. Experiment 3 showed an increase in the magnitude of priming when multiple constraints on activation converged. Experiments 4 and 5 eliminated combinatorial intralexical priming as an alternative explanation. Instead, it was demonstrated that each constraint was influential only insofar as it contributed to the overall semantic representation of the sentence. When the multiple sources of constraint were retained but the sentence-level representation was changed (Experiment 4) or eliminated (Experiment 5), the results of Experiments 1, 2, and 3 and were not replicated. Experiment 6 examined the issue of homonym exposure duration by using an 80-msec stimulus onset asynchrony. The results replicated the previous experiments. The overall evidence indicates that a sentence context can be made strongly and immediately constraining by the inclusion of specific fillers for salient lexical categories. The results are discussed within a constraint-based, context-sensitive model of lexical ambiguity resolution.     

Quantal duration of auditory memories

Neuronal responses in the caudomedial neostriatum (NCM) of adult zebra finches (Taeniopygia guttata) decreased upon repeated, unreinforced presentations of conspecific song, calls, or other complex sounds. This "stimulus-specific habituation" is a form of learning, and its spontaneous loss, a form of "forgetting." Spontaneous forgetting occurred only at narrowly defined times (2 to 3, 6 to 7, 14 to 15, 17 to 18.5, 46 to 48, or 85 to 89 hours after first exposure to a stimulus), determined by stimulus class, number of presentations, and interval between presentations. The first five forgetting times coincided with periods when gene expression and protein synthesis in NCM were required for maintenance of the longer lasting (85 to 89 hours) habituation. The number of successive episodes of gene expression induced by a stimulus, but occurring long after stimulus presentation, appears to determine the quantal duration of auditory memories.     

The temporal dynamics of a visual discrimination: The role of stimulus comparison and opponent processes.

The influence of trial spacing on simple conditioning is well established: When successive reinforced conditioned stimulus, CS+, trials are separated by a short interval (massed training), conditioned responding emerges less rapidly than when such trials are separated by longer intervals (spaced training). This study examined the influence of trial spacing on the acquisition of an appetitive visual discrimination in rats. Experiments 1 and 2 established that massed training facilitates the acquisition of such discriminations. The results of subsequent experiments demonstrated that this trial-spacing effect reflects the proximity of nonreinforced, CS-, trials to preceding (Experiment 3) and signaled (Experiment 4) presentations of the reinforcer. Experiment 5 showed that the facilitation of discrimination learning with massed training reflected an effect on learning rather than performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Processes of overall similarity sorting in free classification.

The processes of overall similarity sorting were investigated in 5 free classification experiments. Experiments 1 and 2 demonstrated that increasing time pressure can reduce the likelihood of overall similarity categorization. Experiment 3 showed that a concurrent load also reduced overall similarity sorting. These findings suggest that overall similarity sorting can be a time-consuming analytic process. Such results appear contrary to the idea that overall similarity is a nonanalytic process (e.g., T. B. Ward, 1983) but are in line with F. N. Milton and A. J. Wills's (2004) dimensional summation hypothesis and with the stochastic sampling assumptions of the extended generalized context model (K. Lamberts, 2000). Experiments 4 and 5 demonstrated that the relationship between stimulus presentation time and overall similarity sorting is nonmonotonic, and the shape of the function is consistent with the idea that the three aforementioned processes operate over different parts of the time course. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A molar entropy model of age differences in spatial memory

Two very-short-term-memory, spatial scanning aging experiments were conducted involving a graphics character as a target stimulus. On the probe portion of a trial, the stimulus was presented in the same position as it was on the target portion of the trial (i.e., a same trial) 50% of the time. However, on the remaining 50% of the trials, the probe stimulus was shifted (or transposed) 1, 2, or 3 positions to the right or left of the original presentation (target) position. In Experiment 1, exposure duration was manipulated. In Experiment 2, the number of potential target display positions was manipulated. For both experiments, older adults showed larger transposition distance effects than younger adults for errors. In the past (e.g., P.A. Allen, 1990, 1991), this effect has been attributed to higher levels of internal noise (entropy) in older than younger adults. This research provides converging operations to this contention by using statistical physics methods to rigorously compute the entropy in a molar neural network across age groups. After successfully fitting the statistical mechanics model to the data, the model is proved to have external validity by fitting a simplified version of it to an earlier spatial memory aging experiment reported by P. R. Bruce and J. F. Herman (1986). The results of both traditional reaction time and error rate analyses, as well as the entropy modeling analyses, indicated that older adults exhibited higher levels of entropy than did the younger adults and that this effect appeared to be generalized across processing stage.     

Spontaneous recovery but not reinstatement of the extinguished conditioned eyeblink response in the rat.

Reinstatement—the return of an extinguished conditioned response (CR) after reexposure to the unconditioned stimulus (US)—and spontaneous recovery—the return of an extinguished CR with the passage of time—are 2 of 4 well-established phenomena that demonstrate that extinction does not erase the conditioned stimulus (CS)–US association. However, reinstatement of extinguished eyeblink CRs has never been demonstrated, and spontaneous recovery of extinguished eyeblink CRs has not been systematically demonstrated in rodent eyeblink conditioning. In Experiment 1, US reexposure was administered 24 hr prior to a reinstatement test. In Experiment 2, US reexposure was administered 5 min prior to a reinstatement test. In Experiment 3, a long, discrete cue (a houselight), present in all phases of training and testing, served as a context within which each trial occurred to maximize context processing, which in other preparations has been shown to be required for reinstatement. In Experiment 4, an additional group was included that received footshock exposure, rather than US reexposure, between extinction and test, and contextual freezing was measured prior to test. Spontaneous recovery was robust in Experiments 3 and 4. In Experiment 4, context freezing was strong in a group given footshock exposure but not in a group given eye shock US reexposure. There was no reinstatement observed in any experiment. With stimulus conditions that produce eyeblink conditioning and research designs that produce reinstatement in other forms of classical conditioning, we observed spontaneous recovery but not reinstatement of extinguished eyeblink CRs. This suggests that reinstatement, but not spontaneous recovery, is a preparation- or substrate-dependent phenomenon. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Analysis of the role of associative inhibition in perceptual learning by means of the same-different task.

In Experiment 1a, participants were exposed, over a series of trials, to separate presentations of 2 similar checkerboard stimuli, AX and BX (where X represents a common background). In one group, AX and BX were presented on alternating trials (intermixed), in another, they were presented in separate blocks of trials (blocked). The intermixed group performed to a higher standard than the blocked group on a same-different test. A superiority of intermixed over blocked exposure was also evident in a within-subject design (Experiment 1b) and when the test required discrimination between a preexposed stimulus and the background (e.g., AX vs. X), even if the background changed between preexposure and test (AY vs. Y) (Experiment 2). In Experiment 3, the intermixed/blocked effect was observed when, in preexposure, stimulus presentations were alternated with the background alone (e.g., AX/X). This suggests that the perceptual learning effect is not the consequence of inhibitory associations between unique features but to increased salience of those features. Experiment 4 confirmed this finding and also ruled out an account of the effect in terms of trial spacing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Exposure and affect: Overview and meta-analysis of research, 1968–1987.

A review and meta-analysis of methodological and subject variables influencing the exposure–affect relationship was performed on studies of the mere exposure effect published in the 20 years following R. B. Zajonc's (see record 1968-12019-001) seminal monograph. Stimulus type, stimulus complexity, presentation sequence, exposure duration, stimulus recognition, age of subject, delay between exposure and ratings, and maximum number of stimulus presentations all influence the magnitude of the exposure effect. Implications of these findings are discussed in the context of previous reviews of the literature on exposure effects and with respect to prevailing theoretical models of the exposure–affect relationship. Modifications of the 2-factor model of exposure effects that increase the heuristic value of the model are described. A possible evolutionary basis of the exposure effect is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Time, capacity, and selection between perceptual attributes

Three experiments were run to determine whether time and central-processing capacity are requried to select between perceptual attributes. A same-different matching task was employed for all experiments. In Experiments 1 and 2, three sets of stimulus pairs were used, each of which varied along only one relevant perceptual dimension (color, size, or form). In Experiment 1, reaction time on the matching task was shown to be faster when the stimuli were presented in blocks in which all stimulus pairs came from the same set (blocked presentation) than when stimulus pairs from each of the three sets were randomly intermixed (random presentation). In Experiment 2, reaction time on a secondary probe task was faster during the encoding stage of a sequential mathcing task with blocked presentation than with random presentation. Experiment 3 indicated that this outcome could not be attributed to a difference in the number of possible stimulus alternatives. Thus, the results support the hypothesis that time and central-processing capacity are required to select between perceptual attributes.     

Recognition and lexical decision without detection: Unconscious perception?

Stimulus detection and concurrent measures of stimulus recognition were compared to establish whether perception occurs in the absence of detection. The target stimuli were familiar words (Experiments 1 and 2), nonwords (Experiment 3), or both words and nonwords (Experiment 4). On each trial, either a stimulus or a blank field was presented. Ss first decided whether a stimulus had been presented and then made either a forced-choice recognition decision (Experiments 1, 2, and 3) or a lexical decision (Experiment 4). Both words and nonwords were recognized and discriminated following correct decisions (i.e., hits). However, in the absence of stimulus detection (i.e., misses), only words were recognized or discriminated. These qualitatively different patterns of results following hits and misses for words and nonwords suggest that stimulus detection may provide an adequate measure of conscious awareness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Context change as the mechanism of reinstatement in causal learning.

Four experiments were conducted to explore the mechanism of reinstatement in human causal learning. After a retroactive interference treatment in which a stimulus was first followed by an outcome (A+) and then followed by a different outcome (A*), simple exposure to the original outcome (+) in the interference-test context produced partial reinstatement of the first-learned information (A+). When exposure to the outcome took place in a context different from the interference-test context, reinstatement was not observed (Experiment 1). Equivalent results appeared when the outcome presented during reinstatement was different from the one originally related to the stimulus affected by interference, independent of whether the interfering outcome (Experiments 2, 3, and 4) or a new outcome (Experiments 3 and 4) was presented before the test. These results suggest an interpretation of reinstatement in terms of a context change between interference and testing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)