Attention capture by novel stimuli.

In several experiments, observers were given glimpses of 4-word arrays. Accuracy of word localization was tested after each array. Some words, called familiar, appeared many times across the series of arrays; others, called novel, appeared only once. The ratio of novel to familiar words in an array ranged from 0:4 to 4:0. When familiar and novel words were not intermixed (in 0:4 and 4:0 arrays), localization accuracy was higher for familiar words. However, when they were intermixed, especially in 1:3 arrays, accuracy tended to be higher for the novel words. This novel popout effect was the outcome of the suppressed localizability of the familiar words (relative to the 0:4 baseline) and the enhanced localizability of the novel words (relative to the 4:0 baseline). Novel popout may reflect an automatic orientation of attention away from more fluently unfolding regions of the perceptual field (familiar objects) and toward less fluently unfolding regions (novel objects). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attention and retrieval from long-term memory.

Conducted 9 experiments with 152 female volunteers (mean age 44.4 yrs) to investigate the disrupting effect of a secondary task on retrieval from long-term memory. Exps I–V studied the influence of concurrent card sorting or digit span on free recall or paired-associate learning of word lists. Exp VI explored recall probability using a recognition paradigm in which accuracy and latency could be measured simultaneously. Exp VII explored the latency effect with a semantic memory paradigm, and Exp VIII required Ss to make semantic category judgments while retaining sequences of 6 digits. Exp IX examined the effect of concurrent digital load on the rate of generating items from semantic categories. Overall findings reveal that a demanding concurrent task did not reduce the probability of retrieving an item from semantic or episodic memory. However, concurrent load during learning substantially effected recall performance. A concurrent task during retrieval did not have a clear effect on latency. The contrast between the pattern shown by errors and by that shown by latencies suggests that attempts to estimate the attentional demands of any task should be interpreted with considerable caution when based on a single measure, such as performance errors, performance latency, or a response to a probe RT signal. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Latent inhibition, habituation, and sensory preconditioning: A test of priming in short-term memory.

Four experiments, with 136 male Long-Evans hooded rats, tested priming in short-term memory as a model for latent inhibition and habituation. The model postulates that the 2 phenomena result from reduced processing when a representation of the target stimulus is already active (primed) in short-term memory at the time of its presentation. Priming is assumed to depend on the integrity of an association formed between the contextual stimuli and the conditioned stimulus/stimuli (CS) during exposure. Using a procedure that should have overshadowed the context, Exp I found that latent inhibition and habituation were nevertheless maintained when a 2nd CS of either equal or shorter duration overlapped with the target during exposure. In Exps II–IV, sensory preconditioning as well as habituation and latent inhibition were obtained with compound exposure, providing reasonable evidence that the added CS was processed along with the target during exposure. Results are interpreted as being inconsistent with the priming model. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Competitive short-term and long-term memory processes in spatial habituation.

Exposure to a spatial location leads to habituation of exploration such that, in a novelty preference test, rodents subsequently prefer exploring a novel location to the familiar location. According to Wagner's (1981) theory of memory, short-term and long-term habituation are caused by separate and sometimes opponent processes. In the present study, this dual-process account of memory was tested. Mice received a series of exposure training trials to a location before receiving a novelty preference test. The novelty preference was greater when tested after a short, rather than a long, interval. In contrast, the novelty preference was weaker when exposure training trials were separated by a short, rather than a long interval. Furthermore, it was found that long-term habituation was determined by the independent effects of the amount of exposure training and the number of exposure training trials when factors such as the intertrial interval and the cumulative intertrial interval were controlled. A final experiment demonstrated that a long-term reduction of exploration could be caused by a negative priming effect due to associations formed during exploration. These results provide evidence against a single-process account of habituation and suggest that spatial habituation is determined by both short-term, recency-based memory and long-term, incrementally strengthened memory. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Infant imitation after a 1-week delay: Long-term memory for novel acts and multiple stimuli.

Deferred imitation after a 1-week delay was examined in 14-month-old infants. Six actions, each using a different object, were demonstrated to each infant. One of the six actions was a novel behavior that had a zero probability of occurrence in spontaneous play. In the imitation condition, infants observed the demonstration but were not allowed to touch the objects, thus preventing any immediate imitation. After the 1-week delay, infants returned to the laboratory and their imitation of the adult's previous actions was scored. Infants in the imitation condition produced significantly more of the target actions than infants in control groups who were not exposed to the modeling; there was also strong evidence for the imitation of the novel act. From a cognitive perspective deferred imitation provides a means of assessing recall memory and representation in children. From a social-developmental viewpoint the findings illustrate that the behavioral repertoire of infants and their knowledge about objects can expand as a result of seeing the actions of others. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Recognition memory for novel stimuli: The structural regularity hypothesis.

Early studies of human memory suggest that adherence to a known structural regularity (e.g., orthographic regularity) benefits memory for an otherwise novel stimulus (e.g., G. A. Miller, 1958). However, a more recent study suggests that structural regularity can lead to an increase in false-positive responses on recognition memory tests (B. W. A. Whittlesea & L. D. Williams, 1998). In the present study the authors attempted to identify the circumstances under which structural regularity benefits old-new discrimination and those under which it leads to an increase in false-positive responses. The highly generalizable tendency shown here is for structural regularity to benefit old-new discrimination. The increase in false-positive responses for structurally regular novel items may be limited to situations in which regularity is confounded with similarity to studied items. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dishabituating long-term memory for gustatory habituation in the cabbage looper, Trichoplusia ni.

The gustatory rejection response of the cabbage looper, Trichoplusia ni (Lepidoptera: Noctuidae), habituates to antifeedant compounds, allowing for the consumption of deterrent yet nontoxic plant materials. In the present study, we demonstrate that habituation to an antifeedant compound (quinine) persists through the moult between larval instars. As an indirect test of whether the memory was protein synthesis-dependent, we tested whether disrupting protein synthesis would block memory reconsolidation after a reminder. The results indicated that disrupting protein synthesis in habituated larvae following a reminder treatment (reexposure to quinine) eliminated the memory for habituation and restored the antifeedant properties of the quinine. We then examined whether the learned memory could be dishabituated and whether this would disrupt or eliminate long-term memory. We show that 6 hr after exposure to a novel/noxious stimulus (a second antifeedent, xanthotoxin) habituated larvae showed a transient dishabituation-like effect in which the quinine deterred feeding again. However, this effect did not permanently eliminate the habituation produced by the extended exposure as larvae tested 72 hr after xanthotoxin exposure again showed a willingness to consume the quinine treated leaves, indicating that the earlier habituation was still present. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attention and luminance detection: Effects of cues, masks, and pedestals.

Three experiments investigated the effects of attention on the detection of luminance targets in a spatial-cuing paradigm. Gabor patch stimuli of 30, 60, or 90 ms duration, equated for detectability, were presented (a) against a uniform field with a checkerboard backward mask, (b) atop a 15% luminance pedestal with a backward mask, or (c) atop a luminance pedestal with no backward mask. Signal detection analysis showed that detection sensitivity was significantly enhanced at attended locations for all observers when backward masks were used, both when targets were presented against a uniform field and when a pedestal was used. However, when no masks were used there was no cuing advantage of any kind. The results show that the cuing effect in simple detection depends on the use of backward masks, a finding that resolves the inconsistencies previously associated with studies of this type. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Involvement of retrosplenial cortex in forming associations between multiple sensory stimuli.

The retrosplenial cortex (RSP) is highly interconnected with medial temporal lobe structures, yet relatively little is known about its specific contributions to learning and memory. One possibility is that RSP is involved in forming associations between multiple sensory stimuli. Indeed, damage to RSP disrupts learning about spatial or contextual cues and also impairs learning about co-occurring conditioned stimuli (CSs). Two experiments were conducted to test this notion more rigorously. In Experiment 1, rats were trained in a serial feature negative discrimination task consisting of reinforced presentations of a tone alone and nonreinforced serial presentations of a light followed by the tone. Thus, in contrast to prior studies, this paradigm involved serial presentation of conditioned stimuli (CS), rather than simultaneous presentation. Rats with damage to RSP failed to acquire the discrimination, indicating that RSP is required for forming associations between sensory stimuli regardless of whether they occur serially or simultaneously. In Experiment 2, a sensory preconditioning task was used to determine if RSP was necessary for forming associations between stimuli even in the absence of reinforcement. During the first phase of this procedure, one auditory stimulus was paired with a light while a second auditory stimulus was presented alone. In the next phase of training, the same light was paired with food. During the final phase of the procedure both auditory stimuli were presented alone during a single session. Control, but not RSP-lesioned rats, exhibited more food cup behavior following presentation of the auditory cue that was previously paired with light compared with the unpaired auditory stimulus, indicating that a stimulus-stimulus association was formed during the first phase of training. These results support the idea that RSP has a fundamental role in forming associations between environmental stimuli. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Aging and memory for frequency of occurrence of novel, visual stimuli: Direct and indirect measures.

Memory for frequency of occurrence typically is investigated using familiar stimuli (e.g., words) and with "direct" tests of memory; that is, the S is required to state explicitly how often an item occurred or which item occurred more often. Exps 1 and 2 examined the effects of age on the ability to make judgments (i.e., direct tests) regarding the frequency of occurrence of words and of novel, visual stimuli (Japanese ideograms). In Exp 3, young and old Ss were compared on "indirect" measures of memory for frequency of occurrence of these ideograms, as indexed by the mere exposure effect. On the direct test of memory, elderly and young Ss did not differ when shown words, but elderly were impaired compared with young Ss when ideograms were presented. When tested indirectly, both groups were sensitive to the frequency of occurrence of ideograms. The pattern of results replicates and extends previous findings regarding performance dissociations between direct and indirect measures of memory in aging. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Contextual effects in conditioning, latent inhibition, and habituation: Associative and retrieval functions of contextual cues.

Rats were used as subjects in four experiments to investigate the transfer of learning from one context to another. Subjects received two sessions of training each day, one in each of two different contexts. Experiment 1 showed that the habituation of the unconditioned response to a stimulus presented in one context was left intact when the stimulus was presented in another context, but that latent inhibition was attenuated when preexposure and conditioning phases occurred in different contexts. Experiments 2 and 3 demonstrated that a conditioned response made on the basis of an appetitive reinforcer was diminished when conditioning and testing occurred in different contexts, but that aversive conditioning was not influenced by the context in which testing occurred. In Experiment 4, the presence of an aversive reinforcer during training did not preclude the occurrence of context-specific conditioning on the basis of an appetitive reinforcer. Associative and retrieval-based interpretations of the results are explored. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of stimulus complexity and familiarization time on infant preferences for novel and familiar stimuli.

Measures of visual fixation (VF) and of focused manipulation of an array of familiar and of novel toys were evaluated for 32 8-mo-olds and 32 12-mo-olds for whom both arrays contained 3 toys and 32 12-mo-olds for whom both arrays contained 5 toys. Prior to testing, half of the Ss in each group had been habituated to the familiar array, whereas the other half had been familiarized but interrupted before habituation could be completed. Results show that habituated Ss in each group preferred to look at and manipulate toys in a novel array. In contrast, interrupted Ss preferred toys in a familiar array, but only if the array was complex relative to age (3 toys for 8-mo-olds and 5 toys for 12-mo-olds) and only with the focused manipulation measure. If the stimulus was simple and/or the response measured was VF, interrupted Ss showed no preference for either array. Findings provide evidence of a progression from familiarity preference to novelty preference that is not tied to a particular age but occurs repeatedly as new stimuli are encountered. Age-related changes are present, however, in the effective complexity of the stimuli, the amount of familiarization, and the form of response necessary to elicit the progression. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Affective habituation: Subliminal exposure to extreme stimuli decreases their extremity.

Following a functional perspective on evaluation, the authors hypothesized that subliminal exposure to extreme stimuli (e.g., extremely negative or positive words) would lead these stimuli to be perceived as less extreme. This process--affective habituation--was tested in 4 experiments. In Experiment 1, participants were subliminally exposed to extremely positive and extremely negative words. In a subsequent explicit-judgment task, these words were rated as less extreme than extreme words that had not been presented. In Experiment 2, these results were replicated with an implicit evaluation measure. In Experiments 3 and 4, subliminal exposure to extreme positive and negative words made the words "behave" as words that are only moderately positive or negative. Several implications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Unintended influences of perception and memory: Attention, awareness, and control.

There has been a great deal of recent interest in the finding of dissociations between performance on implicit or indirect and explicit or direct tests of memory. Implicit tests are said to primarily reflect automatic or unconscious uses of memory, whereas explicit tests primarily reflect strategic or consciously-controlled uses of memory. Rather than identify different processes with different tasks, as is done by use of the implicit/explicit distinction, we have developed a method for separating the within-task contributions of unconscious and consciously-controlled influences. Our general approach starts with the assumption that unconscious or automatic influences and consciously-controlled influences make independent contributions to performance. Several experiments were reported to show the utility of the process-dissociation procedures. Among the findings of those experiments is that conditions traditionally associated with automaticity do have differential effects on consciously-controlled and unconscious (automatic) influences, as measured by the process-dissociation procedure. Other experiments were used to illustrate potential advantages of the process-dissociation procedure over reliance on implicit tests as a means of investigating unconscious influences. Still other experiments were briefly described to show that the process-dissociation procedure can be extended to separate the contributions of consciously-controlled and unconscious influences in a wide variety of domains. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contextual control of long-term habituation in rats.

This study examined contextual control of long-term habituation and whether such effects are dependent on the habituating response system. Habituation of the acoustic startle response transferred from the home cage to the testing context, whereas habituation of lick suppression was context specific (Experiments 1 and 2). Contextual control of habituation was demonstrated between 2 experimental contexts for lick suppression to a tone (Experiment 3) and bar-press suppression to a light (Experiment 4). Experiment 5 extinguished habituation of lick suppression and the orienting response to a tone with 27 exposures to the habituation context. Context specificity of both responses also was found. Previous failures to demonstrate contextual control of habituation may be due to the choice of response system and to less sensitive procedures to detect response recovery. The habituation mechanism for startle is independent from the process or processes that underlie habituation in other response systems, but the nature of these mechanisms is not yet known. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The cognitive consequences of envy: Attention, memory, and self-regulatory depletion.

In a series of 4 experiments, we provide evidence that—in addition to having an affective component—envy may also have important consequences for cognitive processing. Our first experiment (N = 69) demonstrated that individuals primed with envy better attended to and more accurately recalled information about fictitious peers than did a control group. Studies 2 (N = 187) and 3 (N = 65) conceptually replicated these results, demonstrating that envy elicited by targets predicts attention and later memory for information about them. We demonstrate that these effects cannot be accounted for by admiration or changes in negative affect or arousal elicited by the targets. Study 4 (N = 152) provides evidence that greater memory for envied—but not neutral—targets leads to diminished perseverance on a difficult anagram task. Findings demonstrate that envy may play an important role in attention and memory systems and deplete limited self-regulatory resources available for acts of volition. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Interaction between drug discriminative stimuli and exteroceptive, sensory signals.

Interactions between drug discriminative stimuli based on 5.6 and 10 mg/kg sodium pentobarbital (ip) and exteroceptive stimuli (visual and auditory) were studied in 27 male Sprague-Dawley rats in a T-maze. In 3 groups, visual stimuli (light vs dark) were differentially paired with drug stimuli; the 4th group discriminated combinations of tonal frequencies (1 kHz or 10 kHz) and the presence or absence of pentobarbital (10 mg/kg). In general, visual stimuli controlled choice behavior (left or right turn) to a greater extent than did the drug training stimuli, whereas the auditory stimuli exerted no apparent control over the pentobarbital stimulus in Group 4. Tests with higher doses (13.75 and 17.5 mg/kg) indicated augmented stimulus control by the drug dimension in 2 groups (Group 1, 10 mg/kg pentobarbital vs saline; Group 2, 5.6 mg/kg vs 10 mg/kg pentobarbital) but not in the 3rd group (5.6 mg/kg pentobarbital vs saline) in the "conflict" situation, in which the exteroceptive conditions signaled one response whereas the drug stimulus signaled the opposite response. Discrimination training with only one of the stimulus dimensions resulted in stimulus control in the following order: 10 mg/kg vs saline?>?5.6 mg/kg vs saline?>?1 kHz vs 10 kHz. This indicates that the auditory stimuli were of marginal significance. It is concluded drugs can compete with exteroceptive, visual stimuli for associative strength. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Odor learning, recall, and recognition memory in young and elderly adults.

Use of an odor learning test and the California Verbal Learning Test in young and elderly adults enabled comparison of age-related effects on recall and recognition memory. Assessment of odor identification further enabled study of which odor function (recall, identification, recognition) is most affected by aging, the odor functions' interrelationships, and predictors of odor recall. Results suggested that both recall and recognition were significantly affected by aging and that the odor-recall decline cannot simply be referred to poor identification. Very similar age-related effect sizes were found for the 3 types of odor functions. Finally, the combined ability to encode, store, and retrieve odors appears to predict overall recall performance (including its identification component) better than do identification and recognition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age-related changes in processing auditory stimuli during visual attention: Evidence for deficits in inhibitory control and sensory memory.

Age-related declines in attention and cognition have been associated with a difficulty in inhibiting the processing of task-irrelevant information (i.e., the inhibitory deficit hypothesis). However, evidence supporting the inhibitory deficit hypothesis remains equivocal, in part because of complexities in examining the processing of irrelevant stimuli using purely behavioral techniques. The effects of age on the processing of task-irrelevant stimuli were examined using scalp-recorded event-related brain potentials. Participants performed a visual discrimination task while standard and deviant auditory stimuli were presented in the background. Deviant auditory stimuli generated a mismatch negativity (MMN) wave that decreased with age, in part because of an age-related enhancement in sensory-evoked responses. The age-related changes in processing task-irrelevant auditory stimuli are consistent with the inhibitory deficit hypothesis and suggest that impaired inhibitory control of sensory input may play a role in the age-related declines in performance during selective attention tasks. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit, long-term spatial contextual memory.

Learning and memory of novel spatial configurations aids behaviors such as visual search through an implicit process called contextual cuing (M. M. Chun & Y. Jiang, 1998). The present study provides rigorous tests of the implicit nature of contextual cuing. Experiment 1 used a recognition test that closely matched the learning task, confirming that memory traces of predictive spatial context were not accessible to conscious retrieval. Experiment 2 gave explicit instructions to encode visual context during learning, but learning was not improved and conscious memory remained undetectable. Experiment 3 illustrates that memory traces for spatial context may persist for at least 1 week, suggesting a long-term component of contextual cuing. These experiments indicate that the learning and memory of spatial context in the contextual cuing task are indeed implicit. The results have implications for understanding the neural substrate of spatial contextual learning, which may depend on an intact medial temporal lobe system that includes the hippocampus (M. M. Chun & E. A. Phelps, 1999). (PsycINFO Database Record (c) 2010 APA, all rights reserved)