In the

       United States Court of Appeals
                   For the Seventh Circuit
                       ____________________

No. 19-1683
DEWAYNE PERRY,
                                                Petitioner-Appellant,

                                   v.

RICHARD BROWN, Warden, Wabash Valley Correctional Facil-
ity,
                                   Respondent-Appellee.
                       ____________________

            Appeal from the United States District Court for the
             Southern District of Indiana, Terre Haute Division.
        No. 2:18-cv-00271-WTL-DLP — William T. Lawrence, Judge.
                       ____________________

      ARGUED JANUARY 29, 2020 — DECIDED FEBRUARY 12, 2020
                   ____________________

      Before BAUER, EASTERBROOK, and BRENNAN, Circuit Judg-
es.
    EASTERBROOK, Circuit Judge. DeWayne Perry, serving a
long sentence for murder, suffers from aphasia, which im-
pairs his ability to speak, write, and understand words. A
stroke in 2009 caused Perry’s aphasia, a condition that rang-
es from moderate limitations to complete disability. How
2                                                  No. 19-1683

limiting Perry’s aphasia is today—or was in 2016 and 2017—
is a central but unresolved issue in this litigation.
     Perry pursued both direct and collateral review in Indi-
ana’s courts. A lawyer was appointed to represent him on
the collateral a^ack, but as far as we can see the lawyer did
nothing for him and eventually bailed out, leaving Perry un-
represented. Assisted in this appeal by volunteers from an
esteemed law firm, Perry tells us that, after his former law-
yer quit and the state judge denied his request for more time,
he tried to dismiss his collateral a^ack without prejudice so
that he could obtain assistance and mount a be^er challenge.
Five months after dismissing the state proceeding, he refiled
it, adding new legal theories. But the state judge dismissed
the renewed application, ruling that the original dismissal
had been with prejudice. Perry then filed in federal court a
petition under 28 U.S.C. §2254, only to have it summarily
dismissed.
    Time during which a properly filed state collateral a^ack
is pending is excluded from the one year available to file in
federal court. See 28 U.S.C. §2244(d)(2). But Perry’s second
state proceeding was not properly filed, the federal judge
determined, because a second or successive collateral a^ack
in Indiana requires judicial permission that Perry did not
seek or obtain. With the time during which Perry pursued
his second application in state court counted against the year
available in federal court, the federal petition is untimely.
   This conclusion, which Perry concedes is correct, led him
to ask the federal judge to excuse his delay. The Supreme
Court has held that equitable tolling, in addition to the statu-
tory criteria, see §2244(d)(1), can extend the one-year period
available for filing. See, e.g., Holland v. Florida, 

No. 19-1683                                                   3

(2010). The Court explained that this means some “extraor-
dinary circumstance”, beyond the applicant’s control, that
prevents timely filing; simple legal errors, such as ignorance
of the federal deadline, do not suffice. 

see also
Conroy v. Thompson, 

, 821 (7th Cir. 2019). Equita-
ble tolling is available only to applicants who diligently tried
to protect their rights. Indiana concedes that Perry has dis-
played all of the diligence needed for tolling but denies that
he encountered any extraordinary circumstance that blocked
timely filing. The district judge agreed with the state.
    The district judge ruled that equitable tolling is possible
only when some “external obstacle”, see Lombardo v. United
States, 

, 552 (7th Cir. 2017), impeded timely fil-
ing. Aphasia is not an “external” obstacle, the judge wrote; it
is instead a limitation within the petitioner. It follows, the
judge thought, that aphasia (and presumably any other men-
tal limitation) never supports equitable tolling.
    Indiana does not defend this reasoning, which is incon-
sistent with the law of the circuit. Many cases have conclud-
ed that an applicant’s mental limitations can support equita-
ble tolling. See, e.g., Mayberry v. DiEmann, 

, 530
(7th Cir. 2018); Schmid v. McCauley, 

, 350 (7th Cir.
2016); Davis v. Humphreys, 

, 498 (7th Cir. 2014).
These cases show that an “external obstacle” is a barrier be-
yond a litigant’s control. The extent of legal information is
controllable; an inmate can go to the prison library and look
up the deadline (or ask the librarian or a jailhouse lawyer to
do so for him). But mental shortcomings may limit a prison-
er’s power to engage in self-help. A prisoner with an IQ of 50
cannot do legal research. A prisoner with global aphasia
4                                                  No. 19-1683

(that is, inability to use or understand any words) could not
even ask someone else to assist him.
    Despite conceding that, in principle, aphasia could meet
the Supreme Court’s standard for equitable tolling, Indiana
insists that the record does not show that Perry has serious
difficulty in using or understanding words. The state ob-
serves that Perry has filed articulate legal documents in both
state and federal court—which is true enough but does not
necessarily reveal Perry’s abilities. His brief in this court is
thorough and well wri^en, but this tells us more about Per-
ry’s lawyers than about Perry. For him the critical period
may be those months when he was trying to represent him-
self in state court and when, he contends, he and the state
judge could not comprehend each other, leading to a dismis-
sal with prejudice when Perry believed that he was still al-
lowed to litigate in state court (and thus to exclude addition-
al time from the year to file in federal court).
    This record does not permit us to distinguish two possi-
bilities: first, that Perry’s difficulties stem from a brain injury
(a^ributable to the stroke) that left him unable to understand
or use language well enough to protect his interests; second,
that Perry’s difficulties stem from his failure to do enough
legal research to understand which time in state court would
be excluded under §2244(d)(2) and which would not. The
former could support tolling, while the la^er would not.
And the district judge, having mistakenly believed that brain
injuries never permit equitable tolling, did not gather the ev-
idence necessary to decide which of these possibilities (or
perhaps some other) explains Perry’s delay. This record does
not contain any medical analysis of Perry’s verbal abilities
during the important times.
No. 19-1683                                                  5

    According to Indiana, a remand to explore these ma^ers
would be pointless, because Perry has defaulted his princi-
pal substantive argument—that his lawyer rendered ineffec-
tive assistance by allowing the state to add a habitual-
offender charge after the deadline had expired. Perry con-
tends that neither tactical nor strategic considerations could
have supported counsel’s decision to allow the prosecutor a
retroactive extension of time, given the risk (later realized)
that a habitual-offender charge would substantially increase
his punishment. (It turned a 55-year sentence into an 85-year
sentence.) We have held that similar decisions by defense
counsel indeed violate the Sixth Amendment. See, e.g., Jones
v. Zatecky, 

(7th Cir. 2019) (citing other cases).
But Indiana contends that Perry has defaulted his ineffec-
tive-assistance argument, which was not presented to the
state judiciary until his unsuccessful a^empt to refile his col-
lateral a^ack after the original dismissal. A procedural de-
fault in state court forecloses federal review, the state ob-
serves, making a remand futile.
    Procedural defaults may be excused under some circum-
stances. A brain injury that prevents a prisoner from comply-
ing with the state’s rules for prosecuting collateral a^acks
may be one such circumstance. We need not decide, because
ineffective assistance of counsel in pursuing an ineffective-
assistance claim is another, when the state funnels ineffec-
tive-assistance claims to collateral review yet does not fur-
nish the prisoner with a second lawyer to review the first’s
performance. See Martinez v. Ryan, 

(2012); Trevino
v. Thaler, 

(2013). We held in Brown v. Brown, 

, rehearing en banc denied, 

(7th Cir.
2017), that Indiana is such a state. The scanty record assem-
bled to date implies that Perry received ineffective (really,
6                                                 No. 19-1683

no) legal aid in pursuing collateral review and therefore did
not receive in state court the sort of help that would enable
Indiana to use his procedural default to block federal review
of an ineffective-assistance claim.
    The district court needs to determine whether a brain in-
jury caused Perry’s delay in seeking review under §2254,
and if so whether circumstances as a whole justify equitable
tolling. Once such a decision has been made, appellate re-
view will be deferential, see 

, but
we cannot act on the district judge’s behalf. Decision will
depend on medical evidence that the record lacks. Because
Perry’s aphasia could frustrate his ability to gather and pre-
sent such evidence on his own, it is appropriate for the dis-
trict court to appoint counsel to assist him. See 18 U.S.C.
§3006A(a)(2)(B); 

.
   The judgment is vacated, and the case is remanded for
proceedings consistent with this opinion.