Effects of aging and depression on mnemonic discrimination ability

Aging and depression have been found to be associated with poorer performance in mnemonic discrimination. In the current study, a two-response format mnemonic similarity test, Cognitive Drug Research MST, was used to compare these effects. Seventy-six participants were tested; with 52 participants in the young group, aged 18–35 years, and 24 participants in the elderly group, aged 55 years or older. Twenty-two young participants and 10 elderly participants met DSM-IV criteria for MDD or dysthymia. Age-related deficits were found for lure identification and speed of response. Differences in speed of responses to lure images were found for younger depressed participants, and depressive symptom severity was found to be negatively associated with lure identification accuracy in the elderly. These findings may be viewed as putative behavioral correlates of decreased pattern separation ability, which may be indicative of altered hippocampal neurogenesis in aging and depression.     

Auditory speed tasks as potential candidates for the study of cognitive ageing

Speed of information processing is an important cognitive ability. It facilitates the efficient operation of higher order cognitive functions, such as reasoning, and is implicated in various models of cognitive decline. The present study considers the potential benefits of expanding the measurement of processing speed to include the auditory modality. It examines the reliability and factorial structure of a variety of auditory and visual speed tasks in a sample of N = 138 older adults aged between 51 and 82 years. Our findings demonstrate that auditory measures can be used to assess processing speed as indexed by existing widely used tests of this ability. Moreover, the inclusion of auditory tasks significantly increases the relationship between processing speed and general cognitive ability. This novel research provides strong evidence of the suitability of auditory speed tasks for the study of cognitive function in older people, and demonstrates the importance of expanding cognitive measurement to include alternate modalities.     

Damasio's error – Prosopagnosia with intact within‐category object recognition

The sudden inability to recognize individual faces following brain damage was first reported in a scientific journal 150 years ago and termed ‘prosopagnosia’ 70 years ago. While the term originally identified a face‐selective neurological condition, it is now obscured by a sequence of imprecisions. First, prosopagnosia is routinely used to define symptoms of individual face recognition (IFR) difficulties in the context of visual object agnosia or other neurological conditions, or even in the normal population. Second, this over‐expansive definition has lent support to a long‐standing within‐category recognition account of prosopagnosia, that is, that the impairment of IFR reflects a general impairment in recognizing within‐category objects. However, stringent experimental studies of classical cases of prosopagnosia following brain damage show that their core impairment is not in recognizing physically similar exemplars within non‐face object categories. Instead, the impairment presents specifically for recognizing exemplars of the category of faces. Moreover, compared to typical observers, the impairment appears even more severe for recognizing individual faces against physically dissimilar than similar distractors. Here, I argue that we need to limit accordingly our definition of prosopagnosia to a clinical (i.e., neurological) condition in which there is no basic‐level object recognition impairment. Other criteria for prosopagnosia are proposed, with the hope that this conservative definition enables the study of human IFR processes in isolation, and supports progress in understanding the nature of these processes.     

To what extent does typicality boost semantic priming effects between members of their categories?

Atypical items of their semantic category yield more generalisation than their typical members when relearning in connectionist networks (Plaut, D. C. (1996). Relearning after damage in connectionist networks: toward a theory of rehabilitation. Brain and Language, 52(1), 25–82) and in empirical studies (Kiran, S., & Thompson, C. K. (2003). The role of semantic complexity in treatment of naming deficits: Training semantic categories in fluent aphasia by controlling exemplar typicality. Journal of Speech, Language, and Hearing Research, 46(4), 773–787). It seems therefore that atypical words provide more information about the overall structure of the semantic category due to their specific and shared features. In this view, atypical primes could strongly facilitate the processing of targets compared to typical primes, because typical primes contain little information about the variation between members within a category. In contrast, three semantic priming experiments in visual word recognition showed an advantage with the typical context, but not with the atypical one. These findings were observed in a variety of tasks, including lexical decision, categorisation and semantic judgment. Our results do not support the findings about generalisation in relearning and suggest that typicality effects in semantic priming mostly come from the activation of representative features of categories.     

Abstraction and the (Misnamed) Language Familiarity Effect

Talkers are recognized more accurately if they are speaking the listeners’ native language rather than an unfamiliar language. This “language familiarity effect” has been shown not to depend upon comprehension and must instead involve language sound patterns. We further examine the level of sound‐pattern processing involved, by comparing talker recognition in foreign languages versus two varieties of English, by (a) English speakers of one variety, (b) English speakers of the other variety, and (c) non‐native listeners (more familiar with one of the varieties). All listener groups performed better with native than foreign speech, but no effect of language variety appeared: Native listeners discriminated talkers equally well in each, with the native variety never outdoing the other variety, and non‐native listeners discriminated talkers equally poorly in each, irrespective of the variety's familiarity. The results suggest that this talker recognition effect rests not on simple familiarity, but on an abstract level of phonological processing.     

弱智儿童视觉图形辨认的实验研究

本研究探讨了不同智商水平的弱智儿童的视觉图形辨认能力的差异,并与同龄正常儿童作了比较。结果表明,智商在31-51,平均智商为41.6,均龄为11.7岁的弱智儿童,在图形以0.05秒速度的呈现条件下,平均辨认正确率为21.4%;在以0.01秒速度呈现的条件下,平均正确率为20.7%。智商在55-75,平均智商为62.0,均龄为10.2岁的弱智儿童,图形以0.05秒速度呈现时,平均辨认正确率为48.5%;在以0.01秒速度呈现时,平均正确率为45.0%。与同均龄的正常儿童比较,无论在哪一种呈现速度条件下,对图形辨认正确率均明显低于正常儿童。     

英语学习不良儿童语音意识假词拼读与单词认知能力的关系研究

本研究探讨了英语学习不良儿童语音技能一语音意识与词汇到达的发展水平及这两项语音技能与其单词认知能力间关系。结果发现,英语学习不良儿童在假词拼读能力发展上存在缺陷．而在语音意识能力的发展方面却表现正常。在对儿童的单词认知能力进行预测时,语音意识和假词拼读能力是较好的效标。     

Nest membership determines the levels of aggression and cooperation between females of a supposedly communal digger wasp

Females of communal and eusocial Hymenoptera differ greatly in the treatment of conspecifics: communal species lack the nest membership-bias treatment via nestmate (NM) recognition, which is typical of eusocial Hymenoptera. Therefore, an analysis of social interactions can suggest whether a given bee or wasp is communal or eusocial. For this reason, we observed females of the digger wasp Cerceris rubida in experimental dyadic encounters. Because this species had previously been labeled "communal," we expected to find little evidence of a NM bias with respect to cooperation or aggression when paired with NMs and non-nestmates (NNM). Contrary to expectation, females were highly cooperative toward NMs and highly aggressive toward NNMs. Variation in the intensity of aggression toward NNMs partially stems from the degree to which the paired females differed in size. From these results and quantitative comparisons with studies on solitary, communal, and eusocial bee species, it appears that C. rubida has a more complex social organization than previously believed and, in particular, that females of this species exhibit NM recognition, a trait associated with eusociality.