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At least 343 records · Page 19Linked to original sources
PubMed2005

PSF-choice: a novel MRI method for shaping point-spread functions in phase-encoding dimensions.

An imaging method to obtain arbitrary point-spread functions (PSFs) in phase-encoding dimensions is described. This method, called PSF-Choice, is particularly relevant for applications, such as spectroscopic imaging, in which only a very few phase encodes are acquired and ringing artifact can be a serious problem. PSF-Choice uses partial 2D RF excitations to produce aliased excitations that are encoded using standard phase-encoding gradients. Theoretically, the PSF of the reconstructed result depends only on the RF excitation profile. Simulations demonstrate that a Gaussian-like PSF can be achieved, eliminating the side lobes that are associated with ringing artifact. It is further shown that neither the spatial resolution (as represented by the width of the PSF) nor the signal-to-noise ratio (SNR) of the method is adversely affected when compared to standard phase encoding. In the sense that the same number of encodes are required as with standard phase encoding, temporal resolution is also maintained. Phantom experiments demonstrate the initial feasibility of the method to eliminate ringing artifact.

Algorithms↗
PubMed1996

The chemokine C10: immunological and functional analysis of the sequence encoded by the novel second exon.

The gene for C10, a member of the beta-chemokine family of cytokines, contains a novel second exon encoding a 16 amino acid sequence which is inserted into the amino-terminal region of the protein. We propose a model of C10 structure in which the sequence encoded by the second exon is located on the surface of the protein where it interacts with receptors and defines the predominant epitope of the C10 protein. To test this model we produced C10 protein without the sequence encoded by the second exon, termed C10(-). Antisera generated against purified C10 recognized C10 protein but reacted only weakly with C10(-) protein. Recognition of C10 protein by C10 antisera was not blocked by pre-incubation with a peptide encoding the C10 second exon, indicating that the predominant epitope was not simply the amino acid sequence encoded by the second exon. Antibodies generated against a peptide encoding the C10 second exon sequence recognized C10 on Western blots; this reaction was competed both by C10 second exon peptide and by C10 protein. Functional studies demonstrated that both C10/FLAG and C10(-)/FLAG elicit chemotaxis of mouse PECs and human PBMCs, but that C10(-)/FLAG appears to be more potent than C10/FLAG. Thus these data are consistent with our model of C10 in which the sequence encoded by the second exon is located on the surface, participates in defining the predominant epitope, and plays a key role in recognizing or activating chemokine receptors.

Animals↗
PubMed1993

Calmodulin isoforms in Arabidopsis encoded by multiple divergent mRNAs.

Three new, unique cDNA sequences encoding isoforms of calmodulin (CaM) were isolated from an Arabidopsis cDNA library cloned in lambda gt10. These sequences (ACaM-4, -5, and -6) represent members of the Arabidopsis CaM gene family distinct from the three DNA sequences previously reported. ACaM-4 and -6 encode full-length copies of CaM mRNAs of ca. 0.75 kb. The ACaM-5 sequence encodes a partial length copy of CaM mRNA that is lacking sequences encoding the amino-terminal 10 amino acids of mature CaM and the initiator methionine. The derived amino acid sequence of ACaM-5 is identical to the sequences encoded by two of the previously characterized ACaM cDNAs, and is identical to TCH-1 mRNA, whose accumulation was increased by touch stimulation. The polypeptides encoded by ACaM-4 and -6 differ from that encoded by ACaM-5 by six and two amino acid substitutions, respectively. Most of the deduced amino acid sequence substitutions in the Arabidopsis CaM isoforms occurred in the fourth Ca(2+)-binding domain. Polymerase chain reaction amplification assays of ACaM-4, -5 and -6 mRNA sequences indicated that each accumulated in Arabidopsis leaf RNA fractions, but only ACaM-4 and -5 mRNAs were detected in silique total RNA. The six different CaM cDNA sequences each hybridize with unique EcoRI restriction fragments in genomic Southern blots of Arabidopsis DNA, indicating that these sequences were derived from distinct structural genes. Our results suggest that CaM isoforms in Arabidopsis may have evolved to optimize the interaction of this Ca(2+)-receptor protein with specific subsets of response elements.

Amino Acid Sequence↗
PubMed1992

Characterization of a Euglena gene encoding a polyprotein precursor to the light-harvesting chlorophyll a/b-binding protein of photosystem II.

A 7.4 kb segment of a Euglena nuclear gene encoding a portion of the polyprotein precursor to the light-harvesting chlorophyll a/b-binding protein of photosystem II (LHCPII) has been isolated and sequenced. Nine exons can be assembled into a continuous open reading frame encoding 113 amino acids of the C-terminus of an LHCPII, followed by 4 complete LHCPIIs. The intron-exon junctions required to maintain maximum amino acid sequence homology between the LHCPIIs encoded by the Euglena genomic clone and Arabidopsis LHCPII do not conform to the consensus splice site sequences present in most eukaryotic organisms. Three types of LHCPIIs are contained within the polyprotein precursor. There is greater than 90% sequence identity at both the protein and nucleic acid level within a type while between types, there is less than 65% sequence identity. All Euglena LHCPIIs contain three hydrophobic membrane-spanning domains in the same positions as found in other LHCPIIs. Hybridization of genomic Southern blots with a probe encoding LHCPII suggests that the Euglena genome encodes a large number (30-50) of LHCPIIs. A probe derived from the 3' end of the sequenced genomic clone hybridizes with equal intensity to 2-3 genomic fragments on Southern blots. The probe encoding LHCPII hybridizes to RNAs of 9.5 and 6.6 kb on northern blots of total RNA while the 3'-end probe hybridizes only to the 6.6 kb RNA. The 6.6 kb LHCPII band detected on northern blots appears to be composed of transcription products derived from 2-3 LHCPII genes. Euglena appears to be unique in that a large number of LHCPIIs are encoded by a small number (3-5) of polyprotein genes.

Amino Acid Sequence↗
PubMed1990

Analysis of the genes encoding the largest subunit of RNA polymerase II in Arabidopsis and soybean.

We have cloned and sequenced the gene encoding the largest subunit of RNA polymerase II (RPB1) from Arabidopsis thaliana and partially sequenced genes from soybean (Glycine max). We have also determined the nucleotide sequence for a number of cDNA clones which encode the carboxyl terminal domains (CTDs) of RNA polymerase II from both soybean and Arabidopsis. The Arabidopsis RPB1 gene encodes a polypeptide of approximately 205 kDa, consists of 12 exons, and encompasses more than 8 kb. Predicted amino acid sequence shows eight regions of similarity with the largest subunit of other prokaryotic and eukaryotic RNA polymerases, as well as a highly conserved CTD unique to RNA polymerase II. The CTDs in plants, like those in most other eukaryotes, consist of tandem heptapeptide repeats with the consensus amino acid sequence PTSPSYS. The portion of RPB1 which encodes the CTD in plants differs from that of RPB1 of animals and lower eukaryotes. All the plant genes examined contain 2-3 introns within the CTD encoding regions, and at least two plant genes contain an alternatively spliced intron in the 3' untranslated region. Several clustered amino acid substitutions in the CTD are conserved in the two plant species examined, but are not found in other eukaryotes. RPB1 is encoded by a multigene family in soybean, but a single gene encodes this subunit in Arabidopsis and most other eukaryotes.

Amino Acid Sequence↗
PubMed1996

Comparison of lantibiotic gene clusters and encoded proteins.

Lantibiotics form a group of modified peptides with unique structures, containing post-translationally modified amino acids such as dehydrated and lanthionine residues. In the gram-positive bacteria that secrete these lantibiotics, the gene clusters flanking the structural genes for various linear (type A) lantibiotics have recently been characterized. The best studied representatives are those of nisin (nis), subtilin (spa), epidermin (epi), Pep5 (pep), cytolysin (cyl), lactocin S (las) and lacticin 481 (lct). Comparison of the lantibiotic gene clusters shows that they contain conserved genes that probably encode similar functions. The nis, spa, epi and pep clusters contain lanB and lanC genes that are presumed to code for two types of enzymes that have been implicated in the modification reactions characteristic of all lantibiotics, i.e. dehydration and thio-ether ring formation. The cyl, las and lct gene clusters have no homologue of the lanB gene, but they do contain a much larger lanM gene that is the lanC gene homologue. Most lantibiotic gene clusters contain a lanP gene encoding a serine protease that is presumably involved in the proteolytic processing of the prelantibiotics. All clusters contain a lanT gene encoding an ABC transporter likely to be involved in the export of (precursors of) the lantibiotics. The lanE, lanF and lanG genes in the nis, spa and epi clusters encode another transport system that is possibly involved in self-protection. In the nisin and subtilin gene clusters two tandem genes, lanR and lanK, have been located that code for a two-component regulatory system. Finally, non-homologous genes are found in some lantibiotic gene clusters. The nisI and spaI genes encode lipoproteins that are involved in immunity, the pepI gene encodes a membrane-located immunity protein, and epiD encodes an enzyme involved in a post-translational modification found only in the C-terminus of epidermin. Several genes of unknown function are also found in the las gene cluster. A database has been assembled for all putative gene products of type A lantibiotic gene clusters. Database searches, multiple sequence alignment and secondary structure prediction have been used to identify conserved sequence segments in the LanB, LanC, LanE, LanF, LanG, LanK, LanM, LanP, LanR and LanT gene products that may be essential for structure and function. This database allows for a rapid screening of newly determined sequences in lantibiotic gene clusters.

ATP-Binding Cassette Transporters↗
PubMed2006

The intersubject and intrasubject reproducibility of FMRI activation during three encoding tasks: implications for clinical applications.

The goal of the present study was to evaluate the inter- and intrasubject reproducibility of FMRI activation for three memory encoding tasks previously used in the context of presurgical functional mapping. The primary region of interest (ROI) was the medial temporal lobe (MTL). Comparative ROIs included the inferior frontal and fusiform gyri which are less affected by susceptibility-induced signal losses than the MTL regions. Eighteen subjects were scanned using three memory encoding paradigms: word-pair, pattern, and scene encoding. Nine subjects underwent repeat scanning. Intersubject reproducibility of FMRI activation was evaluated by examining the percent of subjects who showed activation within a given ROI and the range to which individual laterality indices (LIs) varied from the mean. Intrasubject test-retest reproducibility was evaluated by examining the LI test-retest correlation, the average difference between LIs from two separate imaging sessions, and concordance ratios of activation volumes (R(volume) and R(overlap)). For scene encoding the reproducibility of activation volume and LIs within the MTL were as good as or better than the reproducibility within the fusiform and inferior frontal ROIs. For pattern encoding and word-pair encoding, the reproducibility of activation volume and LIs within the MTL tended to be worse compared to the fusiform and inferior frontal ROIs. The differences in FMRI reproducibility appeared more dependent on the task than the susceptibility effects. The results of this study suggest that FMRI-based assessment of the neural substrates of memory using a scene encoding task may be a useful clinical tool.

Acoustic Stimulation↗
PubMed2001

The comparative genomics of polyglutamine repeats: extreme differences in the codon organization of repeat-encoding regions between mammals and Drosophila.

Polyglutamine repeats within proteins are common in eukaryotes and are associated with neurological diseases in humans. Many are encoded by tandem repeats of the codon CAG that are likely to mutate primarily by replication slippage. However, a recent study in the yeast Saccharomyces cerevisiae has indicated that many others are encoded by mixtures of CAG and CAA which are less likely to undergo slippage. Here we attempt to estimate the proportions of polyglutamine repeats encoded by slippage-prone structures in species currently the subject of genome sequencing projects. We find a general excess over random expectation of polyglutamine repeats encoded by tandem repeats of codons. We nevertheless find many repeats encoded by nontandem codon structures. Mammals and Drosophila display extreme opposite patterns. Drosophila contains many proteins with polyglutamine tracts but these are generally encoded by interrupted structures. These structures may have been selected to be resistant to slippage. In contrast, mammals (humans and mice) have a high proportion of proteins in which repeats are encoded by tandem codon structures. In humans, these include most of the triplet expansion disease genes.

Animals↗
PubMed2001

Molecular properties of Streptococcus thermophilus plasmid pER35 encoding a restriction modification system.

Bacteriophage attack on lactic fermentation bacteria (LFB) is costly to the dairy industry because it results in product loss. One mechanism used by LFB to protect themselves from bacteriophage attack is restriction of foreign DNA. Three plasmids, pER16, pER35, and pER36, from three different strains of the thermotolerant dairy fermentation bacterium Streptococcus thermophilus were sequenced. One of these plasmids, pER35, isolated from S. thermophilus ST135, encoded a type IC restriction-modification (R-M) system very similar to those encoded on plasmids pIL2614 in Lactococcus lactis subsp. lactis and pND861 in Lactococcus lactis biovar diacetylactis. The high degree of identity between the R-M systems encoded on pER35, pIL2614, and pND861 indicated the potential for horizontal transfer of these genes between different species of lactic fermentation bacteria. Similar to the functional R-M system encoded on pIL2614 that protects the mesophilic L. lactis subsp. lactis against phage attack, the R-M system on pER35 most likely functions in the same role in S. thermophilus ST135. The plasmid pER16 was found to encode the specificity subunit of the R-M system, but not the R or M subunits. In addition, all three plasmids encoded proteins that are present on other S. thermophilus plasmids, including a protein for rolling-circle replication (RepA) and a low-molecular-weight stress protein (Hsp). The presence of a complete R-M system encoded on a plasmid in S. thermophilus, a species that often lacks plasmids, is novel and may be beneficial for protecting S. thermophilus from bacteriophage attack under dairy fermentation conditions.

Amino Acid Sequence↗
PubMed1992

Identification and transcriptional mapping of genes encoded at the IR/Us junction of equine herpesvirus type 1.

Two open reading frames (ORFs) encoded at the inverted repeat unique short (Us) junction of the Short (S) region of the equine herpesvirus type 1 genome were identified by DNA sequencing of a 2876 base pair (bp) genomic segment, and transcripts encoding these ORFs were characterized by Northern blot, S1 nuclease, and primer extension analyses. These studies also established the size of each inverted repeat to be 12,768 nucleotides (nts). The IR6 ORF (816 bp), mapping at nts 12,317-11,502 of the S region, is the last gene completely encoded within each inverted repeat and encodes a predicted 30.1-kDa protein of 272 amino acids, which does not exhibit homology to other alphaherpesvirus proteins. IR6 is expressed as an early transcript of 1.2 kb which is detected initially at 1.5 hr p.i. and up to 12 hr p.i. The transcription initiation and termination sites of IR6 were mapped by primer extension and S1 nuclease analyses to nts 12,465 and 11,408, respectively. The first ORF encoded within the Us segment (909 bp; EUS1), mapping at nts 13,397-12,489, encodes a predicted 33.5-kDa protein of 303 amino acids that exhibits 29% identity to the US2 protein of herpes simplex virus 1. EUS1 is expressed as a 2.3-kb mRNA of the gamma-1 class, as its synthesis begins prior to viral DNA replication at 4 hr p.i. but is retarded by phosphonoacetic acid, an inhibitor of viral DNA replication. The Tci and Tct sites of EUS1 were mapped by S1 nuclease analyses to nts 13,637 and 11,408, respectively. Interestingly, this termination site is also utilized by three late mRNAs of 5.8, 3.8, and 1.7 kb which originate within the Us and overlap the IR6 mRNA encoded in the terminal inverted repeat (TR) of the prototype genomic isomer. EUS1 is 3' coterminal with IR6 in the inverted repeat, whereas, the 5.8, 3.8, and 1.7 kb transcripts are 3' coterminal with IR6 of the TR.

Amino Acid Sequence↗
PubMed1991

Selection of secretory protein-encoding genes by fusion with PHO5 in Saccharomyces cerevisiae.

Secretory protein-encoding genes of Saccharomyces cerevisiae have been cloned by a novel procedure that is based on the functional selection of their fusions with acid phosphatase (APase) at the DNA level. DNA fragments that functionally replace the promoter and signal sequence-encoding regions of the PHO5 gene (encoding APase) have been obtained by positive selection from a pool of cloned random DNA fragments. Five unique DNA sequences containing the promoter, and encoding signal sequences have been isolated. We have also isolated the complete gene, SSP120, encoding one of these S. cerevisiae secretory proteins, SSP120. Gene disruption studies have shown that the SSP120 gene is not essential for viability and growth. The SSP120 amino acid (aa) sequence has 13.5% identity with the middle 88-250 aa residues of the chicken glycosylation site-binding protein. However, SSP120 disruption did not affect protein glycosylation in yeast. The present study provides an alternative approach for the isolation of genes encoding secretory proteins, in contrast to classical genetic approaches that require isolation of functionally defective mutations followed by gene isolation by functional complementation. The present procedure should contribute to our understanding of protein sorting by permitting the cloning of genes encoding proteins targeted to different organelles in the secretory pathway.

Acid Phosphatase↗
PubMed1995

Mollusk genes encoding lysine tRNA (UUU) contain introns.

New intron-containing genes encoding tRNAs were discovered when genomic DNA isolated from various animal species was amplified by the polymerase chain reaction (PCR) with primers based on sequences of rabbit tRNA(Lys). From sequencing analysis of the products of PCR, we found that introns are present in several genes encoding tRNA(Lys) in mollusks, such as Loligo bleekeri (squid) and Octopus vulgaris (octopus). These introns were specific to genes encoding tRNA(Lys)(CUU) and were not present in genes encoding tRNA(Lys)(CUU). In addition, the sequences of the introns were different from one another. To confirm the results of our initial experiments, we isolated and sequenced genes encoding tRNA(Lys)(CUU) and tRNA(Lys)(UUU). The gene for tRNA(Lys)(UUU) from squid contained an intron, whose sequence was the same as that identified by PCR, and the gene formed a cluster with a corresponding pseudogene. Several DNA regions of 2.1 kb containing this cluster appeared to be tandemly arrayed in the squid genome. By contrast, the gene encoding tRNA(Lys)(CUU) did not contain an intron, as shown also by PCR. The tRNA(Lys)(UUU) that corresponded to the analyzed gene was isolated and characterized. The present study provides the first example of an intron-containing gene encoding a tRNA in mollusks and suggests the universality of introns in such genes in higher eukaryotes.

Animals↗
PubMed2006

An approach of encoding for prediction of splice sites using SVM.

In splice sites prediction, the accuracy is lower than 90% though the sequences adjacent to the splice sites have a high conservation. In order to improve the prediction accuracy, much attention has been paid to the improvement of the performance of the algorithms used, and few used for solving the fundamental issues, namely, nucleotide encoding. In this paper, a predictor is constructed to predict the true and false splice sites for higher eukaryotes based on support vector machines (SVM). Four types of encoding, which were mono-nucleotide (MN) encoding, MN with frequency difference between the true sites and false sites (FDTF) encoding, Pair-wise nucleotides (PN) encoding and PN with FDTF encoding, were applied to generate the input for the SVM. The results showed that PN with FDTF encoding as input to SVM led to the most reliable recognition of splice sites and the accuracy for the prediction of true donor sites and false sites were 96.3%, 93.7%, respectively, and the accuracy for predicting of true acceptor sites and false sites were 94.0%, 93.2%, respectively.

Algorithms↗
PubMed2005

The influence of encoding strategy on episodic memory and cortical activity in schizophrenia.

BACKGROUND: Recent work suggests that episodic memory deficits in schizophrenia may be related to disturbances of encoding or retrieval. Schizophrenia patients appear to benefit from instruction in episodic memory strategies. We tested the hypothesis that providing effective encoding strategies to schizophrenia patients enhances encoding-related brain activity and recognition performance. METHODS: Seventeen schizophrenia patients and 26 healthy comparison subjects underwent functional magnetic resonance imaging scans while performing incidental encoding tasks of words and faces. Subjects were required to make either deep (abstract/concrete) or shallow (alphabetization) judgments for words and deep (gender) judgments for faces, followed by subsequent recognition tests. RESULTS: Schizophrenia and comparison subjects recognized significantly more words encoded deeply than shallowly, activated regions in inferior frontal cortex (Brodmann area 45/47) typically associated with deep and successful encoding of words, and showed greater left frontal activation for the processing of words compared with faces. However, during deep encoding and material-specific processing (words vs. faces), participants with schizophrenia activated regions not activated by control subjects, including several in prefrontal cortex. CONCLUSIONS: Our findings suggest that a deficit in use of effective strategies influences episodic memory performance in schizophrenia and that abnormalities in functional brain activation persist even when such strategies are applied.

Adult↗
PubMed2003

Definition of displacement probability and diffusion time in q-space magnetic resonance measurements that use finite-duration diffusion-encoding gradients.

In q-space diffusion NMR, the probability P(r,td) of a molecule having a displacement r in a diffusion time td is obtained under the assumption that the diffusion-encoding gradient g has an infinitesimal duration. However, this assumption may not always hold, particularly in human MRI where the diffusion-encoding gradient duration delta is typically of the same order of magnitude as the time offset Delta between encoding gradients. In this case, finite-delta effects complicate the interpretation of displacement probabilities measured in q-space MRI, and the form by which the signal intensity relates to them. By considering the displacement-specific dephasing, , of a set of spins accumulating a constant displacement vector r in the total time Delta+delta during which diffusion is encoded, the probability recovered by a finite-delta q-space experiment can be interpreted. It is shown theoretically that a data analysis using a modified q-space index q=gammadeltaetag, with gamma the gyromagnetic ratio and eta=square root (Delta-delta/3)/(Delta+delta), recovers the correct displacement probability distribution if diffusion is multi-Gaussian free diffusion. With this analysis, we show that the displacement distribution P(r,texp) is measured at the experimental diffusion-encoding time texp=Delta+delta, and not at the reduced diffusion time tr=Delta-delta/3 as is generally assumed in the NMR and MRI literature. It is also shown that, by defining a probability P(y,Delta) that a time t deltac then eta is not equal to square root (Delta-delta/3)/(Delta+delta) which implies that we can no longer obtain the correct displacement probability from the displacement distribution. In the case that /g/=18 mT/m and Delta-delta=5 ms, the parameter deltac in ms is given by "deltac=0.49a2+0.24" where a is the sphere's radius expressed in microm. Simulation of q-space restricted diffusion MRI experiments indicate that if eta=square root (Delta-delta/3)/(Delta+delta), the recovered displacement probability is always better than the Gaussian approximation, and the measured diffusion coefficient matches the diffusion coefficient at time texp=Delta+delta better than it matches the diffusion coefficient at time tr=Delta-delta/3. These results indicate that q-space MRI measurements of displacement probability distributions are theoretically possible in biological tissues using finite-duration diffusion-encoding gradients provided certain compartment size and diffusion encoding gradient duration constraints are met.

Journal Article↗
PubMed2005

Symmetric spatial encoding in ultrafast 2D NMR spectroscopy.

Single-scan multidimensional spectroscopy utilizes spatial dimensions for encoding the indirect-domain internal spin interactions. Various strategies have been hitherto demonstrated for fulfilling the encoding needs underlying this methodology; in analogy with their time-domain counterparts all of them have in common the fact that they proceed monotonically-starting at one end of the sample and concluding at the other. The present manuscript discusses another possibility that arises for the case of amplitude-modulated ultrafast nD NMR, whereby the spatial encoding progresses from both ends of the sample simultaneously towards the center. Such symmetric encoding is compatible with continuous or discrete excitations as well as with homonuclear or heteronuclear correlations, and exhibits a number of advantages vis-à-vis the unidirectional encodings that have been used so far: it originates echoes that are free from large first-order phase distortions, and yields nD peaks possessing a purely-absorptive character. It has the added advantage that for a given indirect-domain spectral resolution it can complete its task in half the time required by a conventional monotonic spatial encoding, leading to potentially important gains in sensitivity. The main features underlying this new spatially symmetric encoding protocol are derived, and its advantages are demonstrated with a series of amplitude-modulated homo- and hetero-nuclear 2D ultrafast NMR examples.

Nuclear Magnetic Resonance, Biomolecular↗
PubMed2004

An electrophysiological investigation of memory encoding, depth of processing, and word frequency in humans.

Memory encoding can be studied by monitoring brain activity correlated with subsequent remembering. To understand brain potentials associated with encoding, we compared multiple factors known to affect encoding. Depth of processing was manipulated by requiring subjects to detect animal names (deep encoding) or boldface (shallow encoding) in a series of Chinese words. Recognition was more accurate with deep than shallow encoding, and for low- compared to high-frequency words. Potentials were generally more positive for subsequently recognized versus forgotten words; for deep compared to shallow processing; and, for remembered words only, for low- than for high-frequency words. Latency and topographic differences between these potentials suggested that several factors influence the effectiveness of encoding and can be distinguished using these methods, even with Chinese logographic symbols.

Adult↗
PubMed2004

Item- and task-level processes in the left inferior prefrontal cortex: positive and negative correlates of encoding.

Activity in the left inferior prefrontal cortex (LIPC) is often thought to reflect processes that support episodic encoding. Functional magnetic resonance imaging (fMRI) was used to test whether processes subserved by LIPC could be negatively related to subsequent memory performance. Specifically, the current experiment explicitly tested the hypothesis that LIPC processing would positively impact encoding when primarily focused towards specific target items (item-level processing), whereas it would negatively impact encoding when primarily focused on the retrieval and instantiation of current task instructions (task-level processing). Two methods were used to identify regions that were sensitive to the two types of processes: a block-level manipulation of encoding task that influenced subsequent memory, and a back-sort procedure. LIPC was sensitive to item- and task-level processing, but not in a way that always facilitates encoding. LIPC was more active for subsequently remembered words than subsequently forgotten words, but it was also more active in a task that emphasized task-level processing relative to a task that emphasized item-level processing, although this former condition led to poorer subsequent memory performance. This pattern indicates that processes subserved by LIPC are not always positively correlated with episodic encoding. Rather, LIPC processes can support both the controlled semantic processing of items and the controlled retrieval of relevant semantic task context. When devoted to the latter, the diversion of LIPC processes to the task level can have a negative consequence for item-level analysis and encoding.

Adult↗