Varieties of semantic ‘access’ deficit in Wernicke’s aphasia and semantic aphasia

Comprehension deficits are common in stroke aphasia, including in cases with (i) semantic aphasia (SA), characterised by poor executive control of semantic processing across verbal and nonverbal modalities, and (ii) Wernicke’s aphasia (WA), associated with poor auditory-verbal comprehension and repetition, plus fluent speech with jargon. However, the varieties of these comprehension problems, and their underlying causes, are not well-understood. Both patient groups exhibit some type of semantic ‘access’ deficit, as opposed to the ‘storage’ deficits observed in semantic dementia. Nevertheless, existing descriptions suggest these patients might have different varieties of ‘access’ impairment – related to difficulty resolving competition (in SA) vs. initial activation of concepts from sensory inputs (in WA). We used a case-series design to compare WA and SA patients on Warrington’s paradigmatic assessment of semantic ‘access’ deficits. In these verbal and non-verbal matching tasks, a small set of semantically-related items are repeatedly presented over several cycles so that the target on one trial becomes a distractor on another (building up interference and eliciting semantic ‘blocking’ effects). WA and SA patients were distinguished according to lesion location in the temporal cortex, but in each group, some individuals had additional prefrontal damage. Both of these aspects of lesion variability – one that mapped onto classical ‘syndromes’ and one that did not – predicted aspects of the semantic ‘access’ deficit. Both SA and WA cases showed multimodal semantic impairment, although as expected the WA group showed greater deficits on auditory-verbal than picture judgements. Distribution of damage in the temporal lobe was crucial for predicting the initially beneficial effects of stimulus repetition: WA cases showed initial improvement with repetition of words and pictures, while in SA, semantic access was initially good but declined in the face of competition from previous targets. Prefrontal damage predicted the harmful effects of repetition: the ability to re-select both word and picture targets in the face of mounting competition was linked to left prefrontal damage in both groups. Therefore, SA and WA patients have partially distinct impairment of semantic ‘access’ but, across these syndromes, prefrontal lesions produce declining comprehension with repetition in both verbal and non-verbal tasks.

Globalization, Agency, and Institutional Innovation: The Rise of Public-Private Partnerships in Global Governance

Public and private actors increasingly cooperate in global governance, a realm previously reserved for states and intergovernmental organizations (IOs). This trend raises fascinating theoretical questions. What explains the rise in public-private institutions and their role in international politics? Who leads such institutional innovation and why? To address the questions, this paper develops a theory of the political demand and supply of public-private institutions and specifies the conditions under which IOs and non-state actors would cooperate, and states would support this public-private cooperation. The observable implications of the theoretical argument are evaluated against the broad trends in public-private cooperation and in a statistical analysis of the significance of demand and supply-side incentives in public-private cooperation for sustainable development. The study shows that public-private institutions do not simply fill governance gaps opened by globalization, but cluster in narrower areas of cooperation, where the strategic interests of IOs, states, and transnational actors intersect.

Commitment of the Mentally Ill in Maine: a History of Public Policy

This paper traces the historical development in the State of Maine of the procedures by which persons found to be mentally unsound can be committed to institutional care against their will. Beginning in 1820 and continuing to the present, specific changes in the statutes governing this area are noted. Both the criminal and civil commitment procedures are dealt with. Following the historical trace, pending legislation relating to the criminal commitment process is examined in detail. Finally, consideration is given to the need for a complete reexamination of the practice of involuntary commitment involving ethical and constitutional issues.