Attention and implicit memory in the category-verification and lexical decision tasks

Prior research on implicit memory appeared to support 3 generalizations: Conceptual tests are affected by divided attention, perceptual tasks are affected by certain divided-attention manipulations, and all types of priming are affected by selective attention. These generalizations are challenged in experiments using the implicit tests of category verification and lexical decision. First, both tasks were unaffected by divided-attention tasks known to impact other priming tasks. Second, both tasks were unaffected by a manipulation of selective attention in which colored words were either named or their colors identified. Thus, category verification, unlike other conceptual tasks, appears unaffected by divided attention, and some selective-attention tasks, and lexical decision, unlike other perceptual tasks, appears unaffected by a difficult divided-attention task and some selective-attention tasks. Finally, both tasks were affected by a selective-attention task in which attention was manipulated across objects (rather than within objects), indicating some susceptibility to selective attention. The results contradict an analysis on the basis of the conceptual-perceptual distinction and other more specific hypotheses but are consistent with the distinction between production and identification priming.     

The effect of generation on long-term repetition priming in auditory and visual perceptual identification

Perceptual implicit memory is typically most robust when the perceptual processing at encoding matches the perceptual processing required during retrieval. A consistent exception is the robust priming that semantic generation produces on the perceptual identification test (Masson & MacLeod, 2002), a finding which has been attributed to either (1) conceptual influences in this nominally perceptual task, or (2) covert orthographic processing during generative encoding. The present experiments assess these possibilities using both auditory and visual perceptual identification, tests in which participants identify auditory words in noise or rapidly-presented visual words. During the encoding phase of the experiments, participants generated some words and perceived others in an intermixed study list. The perceptual control condition was visual (reading) or auditory (hearing), and varied across participants. The reading and hearing conditions exhibited the expected modality–specificity, producing robust intra-modal priming and non-significant cross-modal priming. Priming in the generate condition depended on the perceptual control condition. With a read control condition, semantic generation produced robust visual priming but no auditory priming. With a hear control condition, the results were reversed: semantic generation produced robust auditory priming but not visual priming. This set of results is not consistent with a straightforward application of either the conceptual-influence or covert-orthography account, and implies that the nature of encoding in the generate condition is influenced by the broader list context.     

Implicit memory and depression: preserved conceptual priming in subclinical depression

Depression impairs explicit memory but research on implicit memory is equivocal. Initial studies indicated preserved implicit memory, implying a depressive deficit in intentional but not unintentional forms of memory. Subsequent research indicated that conceptual priming is reduced in depression, implying a deficit in conceptual memory processes be they implicit or explicit. However, the findings with conceptual priming may be compromised by explicit contamination. The present study compared subclinically depressed and non-depressed participants on matched conceptual tests of explicit memory (category-cued recall) and implicit memory (category production). The implicit test was followed by a post-test questionnaire used to categorise participants as test-aware or test-unaware. On the explicit test, the subclinically depressed participants recalled less than the non-depressed participants. The results on the implicit test depended on test-awareness. Among test-unaware participants, conceptual priming was equivalent across the two groups, whereas for the test-aware, non-depressed participants produced significantly more priming than the subclinically depressed. This indicates that when explicit contamination is controlled, depression does not impair conceptual priming. The depressive dissociation between implicit and explicit memory is better accounted for by the difference between intentional and unintentional forms of memory rather than by the difference between conceptual and perceptual memory processes.     

The generation effect: dissociating enhanced item memory and disrupted order memory

Generating stimuli at encoding typically improves memory for occurrence (item memory) but might disrupt memory for order. In three experiments, the relationship between generation and order memory was examined by using familiar stimuli, which give rise to the standard generation advantage in item memory, and unfamiliar stimuli, which do not. The participants generated or read words and non-words in Experiments 1 and 2 and familiar and unfamiliar word compounds in Experiment 3. For the familiar stimuli, generation enhanced item memory (as measured by recognition) but disrupted performance on the order-reconstruction test. For the unfamiliar stimuli, generation produced no recognition advantage and yet persisted in disrupting order reconstruction. Thus, the positive effects of generation on item memory were dissociated from its negative impact on order memory.     

What’s wrong with contemporary philosophy?

Philosophy in the West divides into three parts: Analytic Philosophy (AP), Continental Philosophy (CP), and History of Philosophy (HP). But all three parts are in a bad way. AP is sceptical about the claim that philosophy can be a science, and hence is uninterested in the real world. CP is never pursued in a properly theoretical way, and its practice is tailor-made for particular political and ethical conclusions. HP is mostly developed on a regionalist basis: what is studied is determined by the nation or culture to which a philosopher belongs, rather than by the objective value of that philosopher’s work. Progress in philosophy can only be attained by avoiding these pitfalls.     

An asymmetry between memory encoding and retrieval. Revelation, generation, and transfer-appropriate processing

Transfer-appropriate-processing accounts of memory emphasize the similarity of encoding and retrieval processes, and imply that experimental manipulations should have similar effects on encoding and retrieval. Exceptions to this expectation are thus of great interest, but extant exceptions (produced by studies using divided attention, alcohol, and benzodiazepines) are debatable, single dissociations between encoding and retrieval. The present experiments demonstrate a reversed dissociation, in which the same variable produced opposite effects when implemented at encoding and retrieval. At encoding, participants either solved anagrams of study words or read intact study words. At retrieval, participants likewise solved anagrams or read intact words prior to making recognition memory judgments. Compared with reading intact words, solving anagrams at encoding enhanced later recognition accuracy, whereas solving anagrams at test impaired accuracy. These results were obtained with old/new decisions (Experiment 1) and with confidence ratings (Experiment 2).     

Attention and perceptual implicit memory: effects of selective versus divided attention and number of visual objects

Extant research presents conflicting results on whether manipulations of attention during encoding affect perceptual priming. Two suggested mediating factors are type of manipulation (selective vs divided) and whether attention is manipulated across multiple objects or within a single object. Words printed in different colors (Experiment 1) or flanked by colored blocks (Experiment 2) were presented at encoding. In the full-attention condition, participants always read the word, in the unattended condition they always identified the color, and in the divided-attention conditions, participants attended to both word identity and color. Perceptual priming was assessed with perceptual identification and explicit memory with recognition. Relative to the full-attention condition, attending to color always reduced priming. Dividing attention between word identity and color, however, only disrupted priming when these attributes were presented as multiple objects (Experiment 2) but not when they were dimensions of a common object (Experiment 1). On the explicit test, manipulations of attention always affected recognition accuracy.     

The emergence of item-specific encoding effects in between-subjects designs: perceptual interference and multiple recall tests

The perceptual-interference effect occurs when interference with word perception (by backward masking) enhances later memory for the word. In terms of the item-specific-relational framework (Hunt & McDaniel, 1993), this effect is similar to other manipulations that enhance item-specific encoding (such as the generation effect). One similarity is that item-specific effects typically do not arise in between-subjects designs. However, the present experiment demonstrates that a between-subjects perceptual-interference effect emerges over multiple recall tests. Furthermore, perceptual interference produces both more intertest gains (indexing enhanced item-specific processing) and more intertest losses (indexing disrupted relational encoding) compared with the intact (control) condition. Finally, delaying the mask to a point at which it no longer interferes with perception (266 msec) eliminates both the perceptual-interference recall advantage and the increase in intertest gains. This condition still produces more intertest losses, however. Together, these results imply that a delayed mask disrupts relational encoding but produces no item-specific enhancement, dissociating the two effects of the perceptual-interference manipulation.