Playing with fire: effects of negative mood induction and working memory on vocabulary acquisition

<p>We investigated the impact of emotions on learning vocabulary in an unfamiliar language to better understand affective influences in foreign language acquisition. Seventy native English speakers learned new vocabulary in either a negative or a neutral emotional state. Participants also completed two sets of working memory tasks to examine the potential mediating role of working memory. Results revealed that participants exposed to negative stimuli exhibited difficulty in retrieving and correctly pairing English words with Indonesian words, as reflected in a lower performance on the prompted recall tests and the free recall measure. Emotional induction did not change working memory scores from pre to post manipulation. This suggests working memory could not explain the reduced vocabulary learning in the negative group. We argue that negative mood can adversely affect language learning by suppressing aspects of native-language processing and impeding form-meaning mapping with second language words.</p

Transmission electron microscopy reveals autophagy within <i>Lepr^flox/flox RIP-Cre</i> β-cells.

<p>Pancreas sections from <i>Lepr^flox/flox</i> (A) and <i>Lepr^flox/flox RIP-Cre</i> (B and D) mice were analyzed by transmission electron microscopy (magnification 9300X and 11000X) and quantified (C). Multigranular bodies were numerous in <i>Lepr^flox/flox RIP-Cre</i> β-cells compared to <i>Lepr^flox/flox</i> β-cells (white squares). Events of macroautophagy (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0071075#pone-0071075-g004" target="_blank">Figure 4D</a>, upper inset) and microautophagy (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0071075#pone-0071075-g004" target="_blank">Figure 4D</a>, bottom inset) were captured in <i>Lepr^flox/flox RIP-Cre</i> β-cells. Scale bar = 2 µm (A and B) and 0.5 µm (D). Micrographs are representative of 3 pancreata analyzed per group. Data are expressed as mean ± SEM. Statistical analysis was performed using Student t test, ** p<0.01.</p

Decreased amplitude in intracellular Ca²⁺ responses to tolbutamide in <i>Lepr^flox/flox RIP-Cre</i> adult islets.

<p>A: Representative recordings from a control <i>Lepr^flox/flox</i> islet (solid line) and a <i>Lepr^flox/flox RIP-Cre</i> islet (dotted line) in response to tolbutamide. B: Graph plotting ΔFmax-Fmin of each peak in response to tolbutamide in the population of islets that showed two peaks. Data are expressed as mean ± SEM. Statistical analysis was performed using Student t test, *** p<0.0001. Responses are representative of 22 islets from 4 mice per group.</p

<i>Lepr^flox/flox RIP-Cre</i> pancreatic β-cells display impaired intracellular Ca²⁺ oscillations in response to glucose.

<p>A: [Ca²⁺]_i recordings of a <i>Lepr^flox/flox</i> islet (left panel) and <i>Lepr^flox/flox RIP-Cre</i> islet (right panel) in response to increasing glucose (G) concentrations and potassium chloride (KCl) from adult mice. B and C: Representative [Ca²⁺]_i recordings showing three different regions per islet of a <i>Lepr^flox/flox</i> islet (left panel) and a <i>Lepr^flox/flox RIP-Cre</i> islet (right panel) from adult (B) and neonatal (C) mice. Graphs are representative of 17–20 islets from 3 neonatal mice per group, and 37–38 islets from 3–4 adult mice per group.</p

<i>Lepr^+/+ RIP-Cre</i> mice present impaired β-cell Ca²⁺ signaling in response to glucose and tolbutamide.

<p>A: Representative [Ca²⁺]_i recordings of a <i>Lepr^+/+</i> islet (left panel) and <i>Lepr^+/+ RIP-Cre</i> islet (right panel) in response to increasing glucose (G) concentrations and potassium chloride (KCl) from 5–6 week old mice. B: Representative [Ca²⁺]_i recordings of a <i>Lepr^+/+</i> islet (solid line) and <i>Lepr^+/+ RIP-Cre</i> islet (dotted line) in response to tolbutamide. C: Graph plotting the AUC of the Ca²⁺ transients during the stimulation with tolbutamide. Data are expressed as mean ± SEM. Statistical analysis was performed using Student t test. *** p<0.0001. Graphs are representative of 18–20 islets from 3 mice per group (in response to glucose) and 16–27 islets from 2–3 mice per group (in response to tolbutamide).</p

Similar glucose metabolic rates in islets from <i>Lepr^flox/flox</i> and <i>Lepr^flox/flox RIP-Cre</i> adult mice.

<p>A: Two [NAD(P)H]_i representative recordings of a <i>Lepr^flox/flox</i> islet (solid line) and a <i>Lepr^flox/flox RIP-Cre</i> islet (dotted line) in response to glucose (G) and sodium azide (NaN₃). B: Graph plotting percentage of AUC/min in response to different glucose concentrations and normalized to the maximum reduction level obtained with 3 mM NaN₃. Data are expressed as mean ± SEM. Statistical analysis was performed using Student t test. Graphs are representative of 32–34 islets from 3 mice per group.</p