Memory and metamemory performance in older adults: One deficit or two?

In two separate experiments, three groups of older adults (50-80 years old) were shown lists of forename-surname pairs. At test subjects were cued with the surname and asked whether they knew the forename (prospective evaluation). Subjects attempted recall for those items they claimed to know and rated their confidence in their answer (retrospective evaluation). In Experiment 1 subjects saw the name list on 5 successive occasions and attempted recall after each. The older subjects recalled fewer items, but there were no age differences on retrospective memory evaluation. There was a marginally significant age effect on the prospective memory evaluation, which on closer inspection appeared to be a scaling effect related to recall performance. Experiment 2 verified this conclusion in a sample of older adults taking part in a training study extended over many weeks. The main implication of this work is that studies that compare metamemory accuracy in groups that differ in baseline memory performance should be careful before drawing conclusions about metamemory independently of memory performance.     

Instrumental and expressive representations of aggression: One scale or two?

The Expagg questionnaire was developed to measure a subject's view of their own aggression as a relatively instrumental or relatively expressive act. Two issues have been raised pertaining to the dimensional structure of the questionnaire: the use of principal components analysis on dichotomous responses and the possibility that instrumental and expressive representations might be independent dimensions rather than opposite ends of a single continuum. In study 1, dichotomous Expagg data from 405 subjects were subjected to microfact, principal components, and factor analysis. Each produced a first general factor, and the correlations between the item loadings were in excess of r = .99. In study 2, a 40‐item Likert scale version of Expagg was given to 295 subjects. Principal components analysis, paired item correlations, and subscale correlations suggested partial independence of instrumental and expressive items. Two new 8‐item scales measuring instrumental and expressive representations were constructed that maximise their independence. Potential uses of these revised scales are discussed. Aggr. Behav. 25:435–444, 1999. © 1999 Wiley‐Liss, Inc.     

Transcortical motor aphasia: One or two aphasias?

The name "transcortical motor aphasia" has been used to refer to two different types of language alterations: damage in the left supplementary motor area and Luria's dynamic aphasia. It is proposed that they represent two types of language disturbances different enough to be considered two different forms of aphasia.     

Temperature sensitivity: One subjective continuum or two?

An experiment is reported on the effect of six consecutive days of exposure to distortions of binaural time and intensity cues on the localization function for tones of 350, 1000, and 4000 Hz. Tests were conducted under “free-field” conditions. The changes in auditory spatial orientation indicate that adjustments to binaurally distorted temporal and intensive cues can occur. Reorientation does not appear to depend upon the existence of veridical auditory cues.     

One blue colour channel or two?

Contrary to the general belief that the yellow-blue mechanism has lower spatial resolution than the red-green mechanism, it has been recently claimed that both mechanisms have similar spatial sensitivity (McKeefry et al, 2001 Vision Research 41 245-255). Studying high-spatial-frequency tritanopia (a colour illusion based on spatio-chromatic interactions in human vision), we found strong evidence for the existence of two blue mechanisms-with low and high spatial-frequency resolution. If confirmed, this may resolve the apparent paradox concerning spatial resolution of the yellow-blue mechanism.     

Looking for two targets at the same time: One search or two?

A considerable amount of evidence suggests that, under conditions of high discriminability, subjects are able to process multiple elements in a visual display simultaneously when searching for a single target among distractors. Relatively little emphasis, however, has been placed on the question of whether subjects can search for and detect multiple targets simultaneously. This latter question is the focus of the present report. In two experiments, we compare performance in single-target and multiple-target detection tasks in order to investigate whether or not multiple targets can be detected simultaneously. In Experiment 1, subjects searched for one or two targets that were defined by color. In Experiment 2, subjects searched for a color and/or a letter target. When the two targets were presented in the same location (e.g., a red X when Target 1 was red and Target 2 was an X), they seemed to be detected simultaneously. Implications for object-based processing of visual information are discussed.     

One table or two? scientific anti-realism and Husserl’s phenomenology

Continental Philosophy Review - In this study I argue that Husserl’s phenomenology is compatible with a realistic interpretation of scientific theories. That said, I distinguish between the...     

Production of non-canonical sentences in agrammatic aphasia: limits in representation or rule application?

The study reported here compares two linguistically informed hypotheses on agrammatic sentence production, the TPH [Friedmann, N., & Grodzinsky, Y. (1997). Tense and agreement in agrammatic production: Pruning the syntactic tree. Brain and Language, 56, 397-425.] and the DOP [Bastiaanse, R., & van Zonneveld, R. (2005). Sentence production with verbs of alternating transitivity in agrammatic Broca's aphasia. Journal of Neurolinguistics, 18, 59-66]. To explain impaired production of non-canonical sentences in agrammatism, the TPH basically relies on deleted or pruned clause structure positions in the left periphery, whereas the DOP appeals to limitations in the application of movement rules. Certain non-canonical sentences such as object-questions and object-relative clauses require the availability of nodes in the left periphery as well as movement to these nodes. In languages with relatively fixed word order such as English, the relevant test cases generally involve a coincidence of left periphery and movement, such that the predictions of the TPH and the DOP are identical although for different reasons. In languages with relatively free word order such as German, on the other hand, it is possible to devise specific tests of the different predictions due to the availability of scrambling. Scrambled object sentences, for example, do not involve the left periphery but do require application of movement in a domain below the left periphery. A study was conducted with German agrammatic subjects which elicited canonical sentences without object movement and non-canonical scrambled sentences with object movement. The results show that agrammatic speakers have a particular problem with the production of scrambled sentences. Further evidence reported in the study from spontaneous speech, elicitation of object relatives, questions and passives and with different agrammatic subjects confirms that non-canonical sentences are generally harder to produce for agrammatics. These findings provide evidence in favor of the DOP and it will be argued that a cross-modal explanation of agrammatic deficits is possible if two factors--movement and canonicity--are taken into consideration.     

One concept or two? A reply to Raine

It is suggested that Raine's criticisms of the paper by Barbour-McMullen, Coid and Howard rest on misconceptions, particularly regarding the nature of the supposed conceptual dichotomy between “North American” and “European” concepts of psychopathy. Several points of clarification are offered. It is maintained that psychopathy is indeed a dual, rather than a unitary, concept.     

One or two? A Process View of pregnancy

Philosophical Studies - How many individuals are present where we see a pregnant individual? Within a substance ontological framework, there are exactly two possible answers to this question. The...     

One role or two? The function of psychological separation in role conflict

Student athletes vary in how much they view their academic and athletic role identities as separate from and interfering with each other. The authors investigated the relation of these perceptions to psychological well-being in 200 intercollegiate athletes. Measures included role separation, interference, identity, and well-being. Correlations indicated that interference related negatively to well-being, whereas viewing the roles as distinct related positively to well-being. Regression analyses of demographic and role identity variables also showed a positive association between role separation and well-being, and a significant Separation x Interference interaction. Specifically, role interference was negatively related to well-being for those who viewed the two roles as distinct but unrelated for those who did not. The buffering effects of role separation are discussed.     

Visual short-term memory for two sequential arrays: One integrated representation or two separate representations?

Two dot arrays, each containing a different set of six randomly selected locations from a 5 × 5 matrix, were presented briefly and were separated by an interstimulus interval (ISI) of 0, 200, 500, or 1,500 msec. Subjects were asked to remember these locations and to report whether a probe dot matched the locations in memory. To find out whether the subjects had formed an integrated representation of the two arrays, the probe dot was accompanied by matrix elements from the first array, from the second array, or from both arrays. Memory for Array 1 was significantly impaired when the retrieval context was drawn from Array 2, and vice versa, suggesting that the two arrays were represented separately. This effect was observed only at an ISI of 500 msec or longer. We propose that as Array 1 is better consolidated, its representation becomes more separated from that of Array 2.     

Envy: One or many?

This paper reports conceptual and clinical research about envy. It consists of an examination and comparison of Klein's points of view of 1952, where the feeling of exclusion from the envious object is stressed, and of 1957, based on the split death instinct that is projected onto the envied object. These two approaches are contrasted with the point of view of the author, where envy is understood as the result of a particular kind of object relation, in which the subject registers an asymmetry with its peer, that he considers unfair, due to the biased action of an idealized omnipotent object, on whom the subject depends and that gives to the envied one, and deceives the envious one, leading to experiencing a compound of emotions: hatred, love, sense of unfairness, wish of revenge, helplessness and incapacity of the subject to provide for himself. The mental state just described emerges from clinical observations, and is illustrated with the passage from the Bible where Abel, the envied one, is killed by Cain, the envious one, showing their relationship with Jehovah, biased in his preferences, a situation designated by the author as 'Cain's complex'. In this paper some considerations are also made concerning the modalities of envy: penis envy in women, the relationship between envy and narcissism, the difference between envy and jealousy, and the interpretative handling of envy. To answer the question posed in the title, the conclusion is that envy presents a central nucleus with different elaborative branches.     

One sound or two? Object-related negativity indexes echo perception

The ability to isolate a single sound source among concurrent sources and reverberant energy is necessary for understanding the auditory world. The precedence effect describes a related experimental finding, that when presented with identical sounds from two locations with a short onset asynchrony (on the order of milliseconds), listeners report a single source with a location dominated by the lead sound. Single-cell recordings in multiple animal models have indicated that there are low-level mechanisms that may contribute to the precedence effect, yet psychophysical studies in humans have provided evidence that top-down cognitive processes have a great deal of influence on the perception of simulated echoes. In the present study, event-related potentials evoked by click pairs at and around listeners' echo thresholds indicate that perception of the lead and lag sound as individual sources elicits a negativity between 100 and 250 msec, previously termed the object-related negativity (ORN). Even for physically identical stimuli, the ORN is evident when listeners report hearing, as compared with not hearing, a second sound source. These results define a neural mechanism related to the conscious perception of multiple auditory objects.     

Lexis and Culture: Bound and Determined?

Although never validated by either quantitative or qualitative research, the Sapir-Whorf Hypothesis continues to be a dominant position from which to consider the relationship between language and culture. This paper challenges the Sapir-Whorf Hypothesis, and attempts to show that lexis and culture are not as inextricably bound to each other as is commonly supposed. After considering numerous examples from Spanish, English and Japanese, the model of cultural prototypes is offered as an alternative to the present psycholinguistic paradigm.     

Perceptual magnet and phoneme boundary effects in speech perception: do they arise from a common mechanism?

The question of whether sensitivity peaks at vowel boundaries (i.e., phoneme boundary effects) and sensitivity minima near excellent category exemplars (i.e., perceptual magnet effects) stem from the same stage of perceptual processing was examined in two experiments. In Experiment 1, participants gave phoneme identification and goodness ratings for 13 synthesized English /i/ and /e/ vowels. In Experiment 2, participants discriminated pairs of these vowels. Either the listeners discriminated the entire range of stimuli within each block of trials, or the range within each block was restricted to a single stimulus pair. In addition, listeners discriminated either one-step or two-step intervals along the stimulus series. The results demonstrated that sensitivity peaks at vowel boundaries were more influenced by stimulus range than were perceptual magnet effects; peaks in sensitivity near the /i/-/e/ boundary were reduced with restricted stimulus ranges and one-step intervals, but minima in discrimination near the best exemplars of /i/ were present in all conditions.     

How are inflectional affixes organized in the mental lexicon?: evidence from the investigation of agreement errors in agrammatic aphasics

Recent psycholinguistic studies have provided evidence that regularly inflected words are decomposed into stems and affixes, both of which have their own representations in the mental lexicon. Specific models of the lexical organization of inflectional affixes have, however, only rarely been investigated in psycho- or neurolinguistic work. We test two recently proposed theoretical models: a representation of affixes (i) in default inheritance trees (Corbett and Fraser, 1993) and (ii) in underspecified paradigms (Wunderlich, 1996). Based on an analysis of agreement errors in elicited speech-production data of German agrammatic aphasics, we argue that affixes are organized with respect to the morphosyntactic features they encode. Specifically, our data indicate that inflectional affixes are best captured within an underspecified paradigm.     

Infant directed speech and the development of speech perception: Enhancing development or an unintended consequence?

Infant directed speech (IDS) is a speech register characterized by simpler sentences, a slower rate, and more variable prosody. Recent work has implicated it in more subtle aspects of language development. Kuhl et al. (1997) demonstrated that segmental cues for vowels are affected by IDS in a way that may enhance development: the average locations of the extreme “point” vowels (/a/, /i/ and /u/) are further apart in acoustic space. If infants learn speech categories, in part, from the statistical distributions of such cues, these changes may specifically enhance speech category learning. We revisited this by asking (1) if these findings extend to a new cue (Voice Onset Time, a cue for voicing); (2) whether they extend to the interior vowels which are much harder to learn and/or discriminate; and (3) whether these changes may be an unintended phonetic consequence of factors like speaking rate or prosodic changes associated with IDS. Eighteen caregivers were recorded reading a picture book including minimal pairs for voicing (e.g., beach/peach) and a variety of vowels to either an adult or their infant. Acoustic measurements suggested that VOT was different in IDS, but not in a way that necessarily supports better development, and that these changes are almost entirely due to slower rate of speech of IDS. Measurements of the vowel suggested that in addition to changes in the mean, there was also an increase in variance, and statistical modeling suggests that this may counteract the benefit of any expansion of the vowel space. As a whole this suggests that changes in segmental cues associated with IDS may be an unintended by-product of the slower rate of speech and different prosodic structure, and do not necessarily derive from a motivation to enhance development.