Negative priming and sequence learning

Three experiments used a novel sequence learning task, in which participants responded to changes in location of one visual stimulus whilst ignoring another. Experiment 1 demonstrated negative priming effects in this task, in that responses to individual sequence elements were disrupted when the attended stimulus (e.g., red asterisk) appeared at the location taken by the unattended stimulus (e.g., blue asterisk) on the immediately preceding trial. Experiments 2 and 3 found that negative priming effects extended beyond sensitivity to individual items, suggesting that people may be able to learn about sequential features of ignored events as well as about single events in isolation. The results are discussed in relation to current theories of negative priming.     

Changing beliefs about past public events with believable and unbelievable doctored photographs

Doctored photographs can shape what people believe and remember about prominent public events, perhaps due to their apparent credibility. In three studies, subjects completed surveys about the 2012 London Olympic torch relay (Experiment 1) or the 2011 Royal Wedding of Prince William and Kate Middleton (Experiments 2–3). Some were shown a genuine photo of the event; others saw a doctored photo that depicted protesters and unrest. A third group of subjects saw a doctored photo whose inauthenticity had been made explicit, either by adding a written disclaimer (Experiment 1) or by making the digital manipulation deliberately poor (Experiments 2–3). In all three studies, doctored photos had small effects on a subset of subjects’ beliefs about the events. Of central interest though, comparable effects also emerged when the photos were overtly inauthentic. These findings suggest that cognitive mechanisms other than credibility – such as familiarity misattribution and mental imagery – can rapidly influence beliefs about past events even when the low credibility of a source is overt.     

Repetition Priming Follows Spontaneous but not Prompted Recognition of Familiar Faces

Reaction times to make a familiarity decision to the faces of famous people were measured after recognition of the faces in a pre-training phase had occurred spontaneously or following prompting with a name or other cue. At test, reaction times to familiar faces that had been recognized spontaneously in the pre-training phase were significantly facilitated relative to an unprimed comparison condition. Reaction times to familiar faces recognized only after prompting in the pre-training phase were not significantly facilitated. This was demonstrated both when a name prompt was used (Experiments 1 and 3) and when subjects were cued with brief semantic information (Experiment 2).

Repetition priming was not found to depend on prior spontaneous recognition per se. In Experiment 3, spontaneously recognizing a familiar face did not prime subsequent familiarity judgements when the same face had only been identified following prompting on a prior encounter. In Experiment 4, recognition memory for faces recognized after cueing was found to be over 90% accurate. This indicates that prompted recognition does not yield repetition priming, even though subjects can remember the faces. A fusion of “face recognition unit” and “episodic record” accounts of the repetition priming effect may be more useful than either theory alone in explaining these results.     

Identifying contours from occlusion events

Surface contours specified by occlusion events that varied in density, velocity, and type of motion (rotation or translation) were examined in four experiments. As a fourth experimental factor, there were both figure-motion trials (the occluding surface moved over a stationary background) and background-motion trials (the background moved behind a stationary surface) in each experiment. Displays contained line patterns and rotary motion (Experiment 1), line patterns and translatory motion (Experiment 2), textured surfaces and rotary motion (Experiment 3), and textured surfaces and translatory motion (Experiment 4). Results indicate that contour identifications are more accurate with translation than with rotation, and that background-motion trials are generally easier than figure-motion trials. Although density in all experiments affected identifications in both background- and figure-motion trials, velocity did so in Experiment 4 only. In Experiments 1, 2, and 3, velocity affected identifications in background-motion trials but not in figure-motion trials. In Experiments 3 and 4, the rate of accretion and deletion of texture was a poor predictor of identification accuracy. These results are not consistent with previous accounts of contour perception from occlusion events, and may reflect an involvement of ocular pursuit as a mechanism for registering contour information.     

Extinction of conditioned taste aversions: Effects of concentration and overshadowing

Extinction of conditioned taste aversions was examined as a function of taste concentration and of the presence of an additional taste. The results of Experiment 1 were consistent with previous evidence in that a conditioned aversion to high concentration saline was more persistent in extinction than an aversion to a low concentration. However, when floor effects were avoided the rate of extinction was faster for the higher (1%) concentration than for 0.2% saline (Experiment 2), a result consistent with accounts of extinction in other preparations. Three further experiments examined extinction of a conditioned sucrose aversion. The addition of 1% saline, but not of 0.2% saline, to sucrose during extinction produced overshadowing ("protection from extinction"; Experiment 3). Such overshadowing by saline was detected after two, but not after a single extinction trial (Experiment 4). This last finding suggests that under the conditions of the present experiments sweet and salty tastes function as elemental stimuli competing for loss of associative strength. No overshadowing was found when almond (an aqueous odour) was used in place of saline as the added stimulus, even when high concentrations of almond were used that produced observable neophobia (Experiments 5A and 5B).     

After-effects of responding and of withholding responses in C.RT tasks

The effects of response repetition on choice RT were compared in b-reaction and in c-reaction tasks [Experiments I(a) and I(b)]. The difference in RTs for repeated and for non-repeated responses was found to be less for c-reaction than for b-reaction tasks. This seemed to be because in c-reaction tasks subjects can prepare themselves to make the same response on every trial, so that there is little further RT reduction consequent on immediate response repetition. In b-reaction tasks subjects cannot always prepare to make the same response, so that the difference between response repetition RT and responce alteration RT is greater. Experiment II examined transitions between events in a serial, self-paced C.RT task in which subjects made a different response to each of two signals but withheld any response to the onset of a third. In this task responses were faster when they followed other, different responses than when they followed “no go” trials. The results of these experiments allow us to reject, even for very elementary tasks, a simple “S--R connection network” model for the processes involved in the identification of signals and the production of responses to them.     

Duration discrimination of filled and empty auditory intervals: Cognitive and perceptual factors

Adult subjects were presented with two auditory stimuli per trial, and their task was to decide which of the two was longer in duration. An adaptive psychophysical procedure was used. In Experiments 1, 2, and 4, the base duration was 50 msec, whereas in Experiment 3, the base duration was 1 sec. In Experiments 1, 2, and 4, it was found that filled intervals (continuous tones) were discriminated more accurately than empty intervals (with onset and offset marked by clicks). It was concluded that this difference was perceptual rather than cognitive in nature, since performance on filled and empty intervals was not affected by increasing cognitive load in a dual-task procedure (Experiment 2) but was affected by backward masking (Experiment 4). In contrast, the results of Experiment 3 showed that duration discrimination of filled auditory intervals of longer duration was cognitively influenced, since performance was impaired by increasing cognitive load. Implications for notions of perceptual processing and timing mechanisms tanderlying differences in duration discrimination with filled and empty intervals are discussed.     

Duration discrimination of filled and empty auditory intervals: cognitive and perceptual factors.

Adult subjects were presented with two auditory stimuli per trial, and their task was to decide which of the two was longer in duration. An adaptive psychophysical procedure was used. In Experiments 1, 2, and 4, the base duration was 50 msec, whereas in Experiment 3, the base duration was 1 sec. In Experiments 1, 2, and 4, it was found that filled intervals (continuous tones) were discriminated more accurately than empty intervals (with onset and offset marked by clicks). It was concluded that this difference was perceptual rather than cognitive in nature, since performance on filled and empty intervals was not affected by increasing cognitive load in a dual-task procedure (Experiment 2) but was affected by backward masking (Experiment 4). In contrast, the results of Experiment 3 showed that duration discrimination of filled auditory intervals of longer duration was cognitively influenced, since performance was impaired by increasing cognitive load. Implications for notions of perceptual processing and timing mechanism underlying differences in duration discrimination with filled and empty intervals are discussed.     

How infants process addition and subtraction events

Three experiments are described that assess 5‐month‐old infants’ processing of addition and subtraction events similar to those reported by Wynn (1992a ). In Experiment 1, prior to each test trial, one group of infants was shown an addition event (1 + 1) while another group was shown a subtraction event (2 ? 1). On test trials, all infants were shown outcomes of 0, 1, 2 and 3. The results seemed to require one of two dual‐process models. One such model assumed that the infants could add and subtract but also had a tendency to look longer when more items were on the stage. The other model assumed that infants had a preference for familiarity along with the tendency to look longer when more items were on the stage. Experiments 2 and 3 examined the assumptions made by these two models. In Experiment 2, infants were given only the test trials they had received in Experiment 1. Thus, no addition and subtraction or familiarity was involved. In Experiment 3 infants were familiarized to either one or two items prior to each test trial, but experienced no actual addition or subtraction. The results of these two experiments support the familiarity plus more items to look at model more than the addition and subtraction plus more items to look at model. Taken together, these three experiments shed doubt on Wynn’s (1992a ) assertion that 5‐month‐old infants can add and subtract. Instead they indicate the importance of familiarity preferences and the fact that one should be cautious before assuming that young infants have sophisticated numerical abilities.     

The influence of passive preexposure on escape from a Morris pool

In 3 experiments rats were preexposed to the landmarks that surround a Morris pool by being placed on a submerged platform within the pool. They were then required to escape from the pool by swimming to the platform, which was in a location that had not been used during preexposure. Preexposure facilitated subsequent escape from the pool, provided that the platform was not moved during preexposure and the relative position of the landmarks to each other remained constant throughout preexposure. In contrast, if during preexposure the platform was moved from session to session (Experiment 1), or the array of landmarks was altered unsystematically from trial to trial (Experiments 2 and 3), then subsequent learning to escape from the pool was disrupted. These findings suggest that the effects of preexposure to the landmarks in a Morris pool is determined by whether or not they are of relevance for identifying the location of the platform. When they are relevant, then subsequent learning is facilitated, but when they are irrelevant, then subsequent learning is disrupted.     

A philosophical and empirical analysis of subjects' modes of inquiry in wason's 2-4-6 task

Investigations of hypothesis-testing behaviour typically conclude that subjects' methods are characterized by “confirmation bias.” However, these studies (a) relied exclusively upon Karl Popper's philosophy of science, (b) only described subjects' strategies via a falsificationist terminology, and (c) failed to determine subjects' precise intentions in the task situations. Alternative philosophies of science can be used to describe hitherto ignored aspects of rule discovery in Wason's (1960) 2-4-6 task as well as reinterpret findings from previous research. Using Wason's task, Experiment 1 adopted J. S. Mill's inductive methodology in order to assess better the extent of elimination in experimentation. While it was found that subjects did eliminate a large proportion of their hypotheses rather than merely confirm them, Mill's eliminative methods applied to this task failed to account for the entirety of subjects' behaviours. Experiment 2 examined subjects' methods in more depth by asking subjects during the task either to: (1) describe their procedures, (2) select from a list of methodology terms those that best characterized their methods, and (3) state on each learning trial their preferred hypotheses and their subjective assessments that those hypotheses were correct. Although subjects were generally unable to describe their methods of inquiry, they were able to typify them via the methodology terms as if their methods were tacitly held skills. Contrary to presumptions of previous research, analyses indicated that subjects were not testing particular hypotheses on every trial but were often examining possible instances of the rule “at random” or “different from ones examined” to that trial. It is also suggested that subjects' decisions to announce rules and their thematic lines of inquiry be given further consideration by researchers.     

Rats’ visual-spatial working memory: New object choice accuracy as a function of number of objects in the study array

When rats had to find new (jackpot) objects for rewards from among previously sampled baited objects, increasing the number of objects in the sample (study) segment of a trial from 3 to 5 and then to 7 (Experiment 1) or from 3 to 6 and 9 (Experiments 2 and 3) or from 6 to 9 and 12 (Experiment 4) did not reduce rats’ test segment performance. Increasing study segment size improved test segment performance contrary the limited-capacity hypothesis concerning rats’ spatial working memory. This effect occurred when objects either differed visually (Experiments 1, 2, 4) or only by odor (Experiment 3). Rats performed no better than chance in finding a jackpot on their first choice from among three visually different objects in Experiments 1 and 2. Furthermore, results from Experiments 2 and 3 indicate that differences in the probability of finding a jackpot by chance in Experiment 1 were not responsible for failure to find the predicted inverse relationship. Results from Experiment 4 indicate that those from Experiments 2 and 3 were not solely due to size of test arrays. We discussed whether our findings could be attributed to innate foraging or perceptual isolation processes during testing or to perceptual encoding processes during exposure to study segment arrays.     

The effect of the length of to-be-remembered lists and intervening lists on free recall: a reexamination using overt rehearsal

In 3 experiments, the authors investigated the effects of to-be-remembered (TBR) and intervening list length on free recall to determine whether selective rehearsal could explain the previous finding that recall was affected only by TBR list length. In Experiments 1 (covert rehearsal) and 2 (overt rehearsal), participants saw 5- and 20-word lists and had to recall the list prior to that last presented list. In Experiment 3, either 1 or 2 lists were presented, and recall of TBR list was postcued. Recall proportion decreased with increased TBR list length. Moreover, the authors found extended recency effects when recall was replotted by when words were last rehearsed (Experiments 2 and 3) and an effect of intervening list length when rehearsal was reduced (Experiment 3).     

Memorization and “feature selection” in the acquisition of natural concepts in pigeons

Pigeons were trained on a successive discrimination task using complex visual stimuli. In Experiment 1, each photographic slide that contained a person had a corresponding “matched background” slide, one that showed the same scene with the person removed. Birds trained on a human positive discrimination acquired the matched pairs problem, but birds trained on a human negative discrimination performed poorly. This suggests a feature-positive effect for complex stimulus categories. Memorization control groups that were trained on a human-irrelevant discrimination also performed poorly with matched slides. However, subsequent experiments demonstrated that these effects depended on the use of matched pairs of slides. The human-as-feature effect was not obtained when human positive and human negative groups were subsequently trained with non-matched slides (Experiment 2), and memorization control groups acquired a human-irrelevant discrimination when trained with nonmatched slides (Experiment 3). Additional tests conducted in Experiments 2 and 3 found that performance was not disrupted when either the reinforced or nonreinforced slides were replaced. This effect was obtained when the category was relevant to the discrimination (Experiment 2) and when the category was irrelevant to the discrimination (Experiment 3). Finally, Experiment 4 demonstrated that memorization of a set of slides is possible when slides are sufficiently dissimilar, (i.e., nonmatched) but performance is not as good when the category exemplars are irrelevant to the discrimination.     

Interference by process, not content, determines semantic auditory distraction

Distraction by irrelevant background sound of visually-based cognitive tasks illustrates the vulnerability of attentional selectivity across modalities. Four experiments centred on auditory distraction during tests of memory for visually-presented semantic information. Meaningful irrelevant speech disrupted the free recall of semantic category-exemplars more than meaningless irrelevant sound (Experiment 1). This effect was exacerbated when the irrelevant speech was semantically related to the to-be-remembered material (Experiment 2). Importantly, however, these effects of meaningfulness and semantic relatedness were shown to arise only when instructions emphasized recall by category rather than by serial order (Experiments 3 and 4). The results favor a process-oriented, rather than a structural, approach to the breakdown of attentional selectivity and forgetting: performance is impaired by the similarity of process brought to bear on the relevant and irrelevant material, not the similarity in item content.     

Circumventing resistance: Using values to indirectly change attitudes

Most research on persuasion examines messages that directly address the attitude of interest. However, especially when message recipients are inclined to resist change, indirect methods might be more effective. Because values are rarely attacked and defended, value change could serve as a useful indirect route for attitude change. Attitudes toward affirmative action changed more when the value of equality was attacked (indirect change) than when affirmative action was directly attacked using the same message (Experiments 1-2). Changes in confidence in the value were responsible for the indirect change when the value was attacked (controlling for changes in favorability toward the value), whereas direct counterarguments to the message were responsible for the relative lack of change when the attitude was attacked directly (Experiment 2). Attacking the value of equality influenced attitudes toward policies related to the value but left policy attitudes unrelated to the value unchanged (Experiment 3). Finally, a manipulation of value confidence that left attitudes toward the value intact demonstrated similar confidence-based influences on policies related to the value of freedom (Experiment 4). Undermined value confidence also resulted in less confidence in the resulting policy attitudes controlling for the changes in the policy attitudes themselves (Experiments 3 and 4). Therefore, indirect change through value attacks presented a double threat-to both the policy attitudes and the confidence with which those policy attitudes were held (potentially leaving them open to additional influence). (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

The effect of cue-familiarity, cue-distinctiveness, and retention interval on prospective remembering

Five experiments investigated the effects of cue familiarity, cue distinctiveness, and retention interval on prospective remembering. Results showed that (1) performance in a prospective memory task is facilitated when the cue is unfamiliar and/or distinctive; and (2) it is impaired by 3-minutes' delay between the instructions and the task (Experiment 1). A beneficial effect of distinctiveness was also found when perceptual rather than semantic distinctiveness was tested (Experiment 2). Experiments 3 and 4 ruled out the hypotheses that “unfulfilled expectancy” of an event (i.e. non-appearance of the cue during training) (Experiment 3), or some sort of “habituation” in the target context (Experiment 4), may have caused the low performance observed in the delayed conditions. Finally, results from Experiment 5 showed that delay negatively affected prospective remembering when it was filled with either a demanding interpolated activity (practice in a STM task) or an undemanding motoric activity (repetitive hands movements). Unfilled delay and an undemanding verbal activity (counting) were found not to affect prospective memory. Implications for the mechanisms underlying prospective remembering are discussed.     

A negative order-repetition priming effect: inhibition of order in unattended auditory sequences?

A novel negative priming (NP) effect is reported in which serial recall for a sequence of visually presented digits was poorer if the same sequence was presented as an irrelevant auditory sequence on the previous trial (Experiments 1 and 2). The effect was enhanced when attention was divided between the to-be-repeated auditory sequence and the concurrent to-be-remembered (TBR) sequence (Experiment 3). When the TBR sequences were also presented auditorily, NP arose only when the repeated TBR sequence was in the same voice as the previous irrelevant sequence; a voice mismatch produced positive priming (Experiment 4). The results suggest that the order of auditory events is registered preattentively and that inhibition may be applied to the acoustic transitions between irrelevant events.     

Infants detect changes in everyday scenes: The role of scene gist

When watching physical events, infants bring to bear prior knowledge about objects and readily detect changes that contradict physical rules. Here we investigate the possibility that scene gist may affect infants, as it affects adults, when detecting changes in everyday scenes. In Experiment 1, 15-month-old infants missed a perceptually salient change that preserved the gist of a generic outdoor scene; the same change was readily detected if infants had insufficient time to process the display and had to rely on perceptual information for change detection. In Experiment 2, 15-month-olds detected a perceptually subtle change that preserved the scene gist but violated the rule of object continuity, suggesting that physical rules may overpower scene gist in infants’ change detection. Finally, Experiments 3 and 4 provided converging evidence for the effects of scene gist, showing that 15-month-olds missed a perceptually salient change that preserved the gist and detected a perceptually subtle change that disrupted the gist. Together, these results suggest that prior knowledge, including scene knowledge and physical knowledge, affects the process by which infants maintain their representations of everyday scenes.