To send content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about sending content to .
To send content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about sending to your Kindle.
Note you can select to send to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be sent to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Longitudinal studies of first episode of psychosis (FEP) patients are critical to understanding the dynamic clinical factors influencing functional outcomes; negative symptoms and verbal memory (VM) deficits are two such factors that remain a therapeutic challenge. This study uses white-gray matter contrast at the inner edge of the cortex, in addition to cortical thickness, to probe changes in microstructure and their relation with negative symptoms and possible intersections with verbal memory.
T1-weighted images and clinical data were collected longitudinally for patients (N = 88) over a two-year period. Cognitive data were also collected at baseline. Relationships between baseline VM (immediate/delayed recall) and rate of change in two negative symptom dimensions, amotivation and expressivity, were assessed at the behavioral level, as well as at the level of brain structure.
VM, particularly immediate recall, was significantly and positively associated with a steeper rate of expressivity symptom decline (r = 0.32, q = 0.012). Significant interaction effects between baseline delayed recall and change in expressivity were uncovered in somatomotor regions bilaterally for both white-gray matter contrast and cortical thickness. Furthermore, interaction effects between immediate recall and change in expressivity on cortical thickness rates were uncovered across higher-order regions of the language processing network.
This study shows common neural correlates of language-related brain areas underlying expressivity and VM in FEP, suggesting deficits in these domains may be more linked to speech production rather than general cognitive capacity. Together, white-gray matter contrast and cortical thickness may optimally inform clinical investigations aiming to capture peri-cortical microstructural changes.
In Africa, the term dry forest covers vegetation types dominated by a more or less continuous tree cover (70%), experiencing pronounced drought during more than three months per year, and occurring within the savanna biome. They may be called (open) woodlands or (dense) dry forests according to tree density and understory structure (Menaut 1983). The Yangambi classification establishes the following (Boughey, 1957a, b; Monod, 1963; Aubréville, 1965).
A woodland has an upper stratum of deciduous trees of small or medium size, with their crowns more or less touching above a sparse woody understory. Tree density is high enough to affect the herbaceous stratum which differs floristically from the adjacent savanna. The ground layer consists of grasses, herbs and suffrutescent plants in sufficient density to allow for annual burnings. The canopy of a woodland tends to be dominated by one or very few species.
A dry forest, strictly speaking, is defined as a closed stand with several woody strata. The grass layer, when present, is weak and discontinuous, only allowing for episodic and sparse fires. In most cases, the trees of the upper stratum are deciduous whereas the understory is composed of evergreen and/or deciduous shrubs which differ from the canopy floristically. The canopy is multispecific and often devoid of woodland dominants. In both dry forest and woodland, the tree species which make up most of the canopy are present but never dominant in the surrounding savanna.
Some authors have considered dry forests to be a tropophilous extension of the rain forest, with adaptations to xeric conditions in characteristics of stems but not of leaves (Schnell, 1976–7).
Email your librarian or administrator to recommend adding this to your organisation's collection.