Charting the progression in semantic dementia: Implications for the organisation of semantic memory

Abstract

A patient, JL, with the syndrome of semantic dementia was assessed longitudinally over a two-year period. The data presented here address the controversy concerning the hierarchical organisation of semantic memory. On a range of category fluency tests, when first tested JL was just within the normal range on the broadest categories of animals and household items, but was virtually unable to produce any instances of specific categories such as breeds of dog or musical instruments. Longitudinal fluency data for the animal category demonstrate that while JL continued to produce the most prototypical responses (cat, dog, horse), other animal labels dropped out early from his vocabulary. On the picture-sorting tests from our semantic memory test battery, JL's discrimination between living things and man-made objects was preserved for a substantial time in conjunction with a marked decline in his sorting ability for more specific categories, particularly features or attributes (e.g. size, foreign-ness, or ferocity of animals).

An analysis of naming responses to the 260 Snodgrass and Vanderwart pictures on four occasions suggests a progressive loss of the features of semantic representations that enable discrimination between specific category instances. There was a progressive decline in circumlocutory and category co-ordinate responses with a rise in broad superordinate and cross-category errors. The latter are of particular theoretical interest; on session I, all cross-category errors respected the living/man-made distinction, but by session IV almost half of such errors failed to respect this distinction. The emergence of category prototypes was another notable feature, particularly in the living domain: at one stage, land (or four-legged) animals were all named either cat, dog, or horse. By contrast, within the man-made domain, items were frequently described in terms of their broad use or function, until eventually no defining features were produced. These findings are discussed in the context of competing theories of semantic organisation.     

Intrusive and non‐intrusive memories in a non‐clinical sample: The effects of mood and affect on imagery vividness

We studied the number, valence, and vividness of intrusive and non‐intrusive memories in two groups (N = 20) of pre‐screened non‐depressed mood and depressed mood undergraduate participants. They were asked to generate as many intrusive memories (IMs) as possible from the prior 2 weeks, together with pleasant and unpleasant non‐intrusive memories from the same period. They subsequently formed images of these memories and rated them on measures of vividness, valence, arousal, and overall affect, while having their heart rate, skin conductance, and electromyogram monitored. IMs were common, with participants generating a mean of 1.15 pleasant IMs and 1.60 unpleasant IMs, and there was some evidence that they were mood‐congruent. IMs were more vivid than non‐intrusive memories, a difference not due to either valence or arousal. We conclude that IMs are a general feature of human memory rather than just a symptom of certain clinical disorders.     

Taking the Bull by the Horns: A Family Therapy Case of an East Indian Adolescent Substance Abuser

The cultural clash between traditional East Indian cultural values and US values often leads to parent–child conflicts, which increases East Indian adolescents’ risk for substance abuse. This is demonstrated in theory and through a case presentation of an East Indian adolescent substance abuser who was treated through an approach that coincided with the core principles of multi-dimensional family therapy. Family therapy interventions that coincided with East Indian cultural values were generally effective and resulted in decreased parental substance abuse, decreased family conflict, and improved parenting skills. Family therapy interventions that conflicted with East Indian cultural values were not effective. Further study is needed to ascertain the extent of parental and adolescent substance abuse in East Indian immigrant families and the effectiveness of a multi-dimensional family therapeutic approach to treatment.     

Definition Inclosed: A Reply to Zhong

In ‘Definability and the Structure of Logical Paradoxes’ (Australasian Journal of Philosophy, this issue) Haixia Zhong takes issue with an account of the paradoxes of self-reference to be found in Beyond the Limits of Thought [Priest 1995. The point of this note is to explain why the critique does not succeed. The criterion for distinguishing between the set-theoretic and the semantic paradoxes offered does not get the division right; the semantic paradoxes are not given a uniform solution; no reason is provided as to why the naïve denotation relation is ‘indefinite’ (other than that its definiteness leads to contradiction); and the account of the denotation relation given clearly misses the mark, even by consistent standards.     

Effect of Prenatal Androgen on Adult Personality: Greater Openness with More Female-Typical 2D:4D Digit Ratios

One hundred seven university community participants (71 female, 36 male) were evaluated on the five personality factors (NEO-FFI), and finger lengths were measured to determine the ratio of the second to fourth digit (2D:4D). It is well-established that 2D:4D ratios are an index of prenatal androgenic activity. Sex differences were found such that the men had lower 2D:4D ratios than the women for both the left and right hands, and the women indicated greater Neuroticism than the men, as reported by others. Most interestingly, greater Openness was significantly associated with more female-typical (higher) 2D:4D ratios for the entire sample. This was significant for the male sample alone, and was found at a trend level in the female sample alone.     

The Role of Semantic Clustering in Optimal Memory Foraging

Recent studies of semantic memory have investigated two theories of optimal search adopted from the animal foraging literature: Lévy flights and marginal value theorem. Each theory makes different simplifying assumptions and addresses different findings in search behaviors. In this study, an experiment is conducted to test whether clustering in semantic memory may play a role in evidence for both theories. Labeled magnets and a whiteboard were used to elicit spatial representations of semantic knowledge about animals. Category recall sequences from a separate experiment were used to trace search paths over the spatial representations of animal knowledge. Results showed that spatial distances between animal names arranged on the whiteboard were correlated with inter‐response intervals (IRIs) during category recall, and distributions of both dependent measures approximated inverse power laws associated with Lévy flights. In addition, IRIs were relatively shorter when paths first entered animal clusters, and longer when they exited clusters, which is consistent with marginal value theorem. In conclusion, area‐restricted searches over clustered semantic spaces may account for two different patterns of results interpreted as supporting two different theories of optimal memory foraging.     

From Four‐ to Five‐Dimensionalism

Philosophers have long noticed the similarity of identity over time and identity across worlds. Despite this similarity, analogous views on these matters are not always taken equally seriously. Four‐dimensionalism is one of the most well‐known accounts of identity over time. There is a clear modal analogue of four‐dimensionalism, on which objects are modally extended and their trans‐world identity is a matter of having distinct modal parts located in different possible worlds. Yet this view, which we might call ‘five‐dimensionalism,’ is rarely discussed or defended, in comparison to its temporal counterpart. I argue that five‐dimensionalism is at least as plausible as four‐dimensionalism and deserves serious consideration as an account of trans‐world identity. The strategy is to show that arguments typically used in defence of four‐dimensionalism can be adapted to defend five‐dimensionalism as well. A powerful consideration in favour of four‐dimensionalism is the fact that it provides an elegant and unified solution to a variety of puzzles concerning material coincidence. I show that such puzzles come in equally troubling modal varieties and that five‐dimensionalism provides an equally unified and elegant solution to them. 1     

A Sketch of a Theory of Moral Blameworthiness*

In this paper I sketch an account of moral blame and blameworthiness. I begin by clarifying what I take blame to be and explaining how blameworthiness is to be analyzed in terms of it. I then consider different accounts of the conditions of blameworthiness and, in the end, settle on one according to which a person is blameworthy for φ‐ing just in case, in φ‐ing, she violates one of a particular class of moral requirements governing the attitudes we bear, and our mental orientation, toward people and other objects of significant moral worth. These requirements embody the moral stricture that we accord to these others a sufficient level of respect, one that their moral worth demands. This is a familiar theme which has its roots in P. F. Strawson’s pioneering views on moral responsibility. My development of it leads me to the conclusion that acting wrongly is not a condition of blameworthiness: violating a moral requirement to perform, or refrain from performing, an action is neither necessary nor sufficient for being blameworthy. All we are ever blameworthy for, I will argue, are certain aspects of our mental bearing toward others. We can be said to be blameworthy for our actions only derivatively, in the sense that those actions are the natural manifestations of the things for which we are strictly speaking blameworthy.